Key Determinants of Successful Cardiopulmonary Resuscitation (CPR)
Quality Chest Compressions (100-120/min with 2-2.4” Depth and Full Chest Recoil Between Compressions
Early Defibrillation
American Heart Association Guidelines Recommend Maintaining a Chest Compression Fraction of ≥60% (Meaning on Average, Chest Compressions Should Be Withheld<40% of the Intra-Arrest Time ( J Emerg Med, 2018) [MEDLINE]
There May Be Additional Benefit with Maintaining a Chest Compression Fraction of ≥80% (Circulation, 2009) [MEDLINE] (Resuscitation, 2011) [MEDLINE]
Multiple Interventions May Interrupt Chest Compressions: some of which have unclear benefit
Administration of Resuscitation Medications
Endotracheal Intubation: supraglottic airway insertion can be quicker than endotracheal intubation, don’t interfere with chest compressions, and have a loer complication than endotracheal intubation
Vascular Access Attempts: intraosseous access can be quicker than intravenous access and doesn’t interfere with chest compressions
In Cardiopulmonary Arrest, Systemic and Pulmonary Vascular Perfusion is Very Low Despite Optimal Cardiopulmonary Resuscitation (CPR)
Therefore, Ventilation/Perfusion Relationships Can Be Maintained with Low Minute Ventilation
Hyperventilation Should Be Avoided During CPR, as Increased Intrathoracic Pressure and Gastric Distention Can Impede Effective Chest Compressions (Circulation, 2015) [MEDLINE]
Airway Management Techniques During Cardiopulmonary Resuscitation
Laryngeal Mask Airway (LMA) or Other Similar Supraglottic Airway Device
Clinical Efficacy of Endotracheal Intubation in Out-of-Hospital Cardiac Arrest
Randomized Trial of Bag-Mask Ventilation vs Endotracheal Intubation During Cardiopulmonary Resuscitation in Out-of-Hospital Cardiac Arrest (JAMA 2018) [MEDLINE]: n= 2043
Bag-Mask Ventilation and Endotracheal Intubation were Equivalent in Terms of 28-Day Neurologic Outcome for Out-of-Hospital Cardiac Arrest
AIRWAYS-2 Randomized Trial of Supraglottic Airway Device vs Tracheal Intubation in Out-of-Hospital Cardiac Arrest ( JAMA, 2018) [MEDLINE]: n = 9296
Supraglottic Airway Device and Endotracheal Intubation Were Equivalent in Terms of 30-Day Outcome in Out-of-Hospital Cardiac Arrest
Trial of Laryngeal Tube Insertion vs Endotracheal Intubation in Out-of-Hospital Cardiac Arrest (JAMA, 2018) [MEDLINE]: n= 3000
Laryngeal Tube Insertion was Superior to Endotracheal Intubation in Terms of 72 hr Mortality Rate in Out-of-Hospital Cardiac Arrest
Recommendations (American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care, 2015) (Circulation, 2015) [MEDLINE]
Use the Maximal Feasible Inspired Oxygen Concentration During CPR (Class IIb, LOE C-EO)
Method of Oxygenation/Ventilation
Inadequate Evidence to Demonstrate a Difference in Survival or Favorable Neurologic Outcome with the Use of Bag-Mask Ventilation, as Compared to Endotracheal Intubation During CPR
Either a Bag-Mask Device or an Advanced Airway May Be Used for Oxygenation/Ventilation During CPR in Both the In-Hospital and Out-of-Hospital Settings (Class IIb, LOE C-LD)
For Healthcare Providers Trained in Their Use, Either an Supraglottic Airway Device or an Endotracheal Tube May Be Used as the Initial Advanced Airway During CPR (Class IIb, LOE C-LD)
Confirmation of Endotracheal Tube Placement
Continuous Waveform Capnography is Recommended in Addition to Clinical Assessment as the Most Reliable Method of Confirming and Monitoring Correct Endotracheal Tube Placement (Class I, LOE C-LD)
If Continuous Waveform Capnometry is Not Available, a Nonwaveform CO2 Detector, Esophageal Detector Device, or Ultrasound Used by an Experienced Operator is a Reasonable Alternative (Class IIa, LOE C-LD)
Ventilation After Advanced Airway Placement
After Placement of Advanced Airway, it is Reasonable to Deliver 1 Breath Every 6 sec (10 Breaths/min) While Continuous Chest Compressions are Being Performed (Class IIb, LOE C-LD)
May Be Complicated by Gastric Rupture in Some Cases (Am J Emerg Med, 1993) [MEDLINE]
Back Blows
Chest Thrusts
Clinical Efficacy
Efficacy of a Single Maneuver is 50% at Best, with the Highest Efficacy Observed When Using Multiple Maneuvers (Crit Care Med, 1979) [MEDLINE]
Recommendations for Responsive Patient (2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care) (Circulation, 2010) [MEDLINE] (2015 American Heart Association Guidelines Update for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care) (Circulation, 2015) [MEDLINE]
In a Patient with Severe Airway Obstruction by a Foreign Body, Multiple Rapid-Sequence Abdominal Thrusts Followed by Chest Thrusts is Recommended
If the Abdomen Cannot Be Encircled or the Patient is in the Late Stages of Pregnancy, Chest Thrusts are the Initial Recommended Maneuver
Recommendations for Unresponsive Patient (2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care) (Circulation, 2010) [MEDLINE]
Blind Finger Sweep is Not Recommended, Unless Solid Material Becomes Visible in the Upper Airway During the Course of CPR
Cardiopulmonary Resuscitation (CPR): since chest compressions may produce higher airway pressures than abdominal thrusts in unresponsive patients (Resuscitation, 2000) [MEDLINE]
Head-Tilt Chin-Lift is Frequently the First Maneuver to Utilized in a Patient without a Concern About Possible Cervical Cord Spinal Injury
Technique
Use 2 Hands to Apply Downward Pressure to the Forehead and Use Tips of Index and Middle Fingers to Extend Neck by Lifting Jaw Forward at the Mentum: this maneuver moves the tongue anteriorly out of the posterior pharynx (JACEP, 1976) [MEDLINE]
Jaw-Thrust Maneuver
Background
Jaw Thrust Maneuver Can Be Utilized in a Patient Even if There is a Concern About Possible Cervical Spinal Cord Injury
However, Since Airway Maneuvers are Usually Associated with at Least Some Movement of the Cervical Spine, Caution Must Be Exercised in Any Patient in Whom There is a Concern About Potential Cervical Spinal Cord Injury (Spine; Phila Pa 1976) [MEDLINE] (Anesth Analg, 2000) [MEDLINE]
Technique
With Hands on Parieto-Occipital Skull, Thrusting Jaw Forward (Importantly, without Extending the Neck) Moves the Tongue Anteriorly Out of the Posterior Pharynx (ORL J Otorhinolaryngol Relat Spec, 2005) [MEDLINE]
Airway Adjuncts
General Comments
After Establishment of Upper Airway Patency by the Above Upper Airway Maneuvers, Airway Adjuncts Serve to Maintain Patency
Oropharyngeal Airway
Design
Oropharyngeal Airway is a Tube-Like Plastic Device Which Prevents the Tongue and Oropharyngeal Soft Tissues from Obstructing the Upper Airway
Clinical Use
Oropharyngeal Airway Should Only Be Used in a Patient Under Deep Sedation (Due to the Risk of Vomiting and/or Aspiration)
Sizing
When Held Next to the Patients Face with the Flat End in Line with the Patient’s Mouth, the Tip of a Properly-Sized Oropharyngeal Airway Should Just Reach the Angle of the Mandible
Insertion
Insert the Oropharyngeal Airway Upside Down to Avoid Pushing the Tongue Posteriorly into the Oropharynx
Then Carefully Rotate the Oropharyngeal Airway 180 Degrees While Advancing It into the Posterior Pharynx
Adverse Effects/Complications
Capture of Lips/Tongue Between the Oropharyngeal Airway and Teeth (Causing Injury)
Oropharyngeal Mucosal Injury (May Occur During Rotation): may cause bleeding in a patient with coagulopathy
Inadvertent Displacement of the Tongue into the Posterior Pharynx (Worsening Upper Airway Obstruction)
Use of Incorrectly Size Oropharyngeal Airway
Too Large Oropharyngeal Airway: may push the epiglottis into the airway, worsening upper airway obstruction
Too Small Oropharyngeal Airway: may be ineffective and/or become lost in the oropharynx
Vomiting (with/without Aspiration): may occur in a patient who is not adequately sedated prior to oropharyngeal device insertion
Nasopharyngeal Airway (Nasal Trumpet)
Design
Nasopharyngeal Airway is a Soft Rubber or Plastic Tube Which is Passed Through the Nose into the Posterior Pharynx
Clinical Use
Nasopharyngeal Airway May Be Used in a Patient with Clenched Jaw or Inability to Tolerate an Oropharyngeal Airway (Due to Inadequate Sedation)
Sizing
Nasopharyngeal Airway Comes Sizing is Based on the Internal Diameter: with the larger internal diameter = longer length
Small Adult: 6-7 cm
Medium Adult: 7-8 cm
Large Adult: 8-9 cm
Size Should Be Selected Based on Length of the Nasopharyngeal Airway (Emerg Med J, 2005) [MEDLINE]
When Holding the Nasopharyngeal Airway Next to Patient’s Mandible with the Flared End at the Patient’s Mouth, the Distal Tip of a Properly-Sized Nasopharyngeal Airway Should Just Reach the Angle of the Patient’s Mandible
Insertion
Lubricate the Nasopharyngeal Airway (with Water-Soluble Lubricant or Lidocaine Jelly) and Insert Along the Floor of the Nares into the Posterior Pharynx (Following a Downward Angle of Approximately 15 Degrees): note that the contact time for lidocaine jelly is insufficient to provide anesthesia during the insertion, but it may provide anesthesia after the nasopharyngeal airway is already in place
Adverse Effects/Complications
Inadvertent Intracranial Nasopharyngeal Airway Incursion: has been rarely described in patients with basilar skull fractures
Nasopharyngeal Mucosal Injury: may cause epistaxis in up to 30% of cases (Anaesthesia, 1993) [MEDLINE]
Epistaxis May Be Severe in a Patient with Coagulopathy
Use of Excessively Long Nasopharyngeal Airway (Which May Extend into the Esophagus and Cause Gastric Distention During Subsequent Bag-Valve-Mask Ventilation)
Pre-Intubation Assessment
American Society of Anesthesiologists (ASA) Physical Status Classification
ASA 1: Normal Healthy Patient
Example: varicose veins in otherwise healthy patient
ASA 2: Mild Systemic Disease That Does Not Impair Normal Activity
ASA 4: Severe Systemic Disease That is a Constant Threat to Life
Example: CHF, major organ insufficiency, etc
ASA 5: Moribund Patient Who is Not Expected to Survive for 24 hrs With or Without Surgery
Example: intracranial hemorrhage in coma, etc
ASA 6: Declared Brain Dead with Plan for Organ Donation
Assessment for Physiologic Factors Which May Increase the Risk of Intubation
Physiologic Risk Factors Which Increase the Risk of Cardiovascular Compromise During or After Airway Management, Regardless of Anatomic Difficulty with Endotracheal Intubation (West J Emerg Med. 2015;16(7):1109 [MEDLINE]
Technique: assessed in upright patient with mouth wide open and tongue out -> allows assessment of oral size and anatomy of tongue and oropharynx
Class I: hard palate, soft palate, entire uvula, fauces, and pillars visible
Class II: hard palate, soft palate, part of uvula, and fauces visible
Class III: hard palate, soft palate, and base of uvula visible -> predicts difficult mask ventilation and difficult intubation
Class IV: only hard palate visible -> predicts difficult mask ventilation and difficult intubation
Clinical Efficacy
In Non-Cardiac Arrest Emergency Department Intubations, Only 32% of Patients were Able to Follow Simple Commands (Allowing Mallampati Assessment) and Not Cervical Spine Immobilized (Allowing Neck Mobility and Thyromental Measurement) (Ann Emerg Med, 2004) [MEDLINE]
In Emergency Department Intubations, Mallampati Could Be Performed in Only 26% of Patients, Due to Lack of Patient Cooperation and Clinical Instability (J Emerg Med, 2010) [MEDLINE]
In Terms of Predicting Difficulty to Intubate, Modified Mallampati Score (≥3) had a Positive Likelihood Ratio 4.1 (95% CI: 3.0-5.6) and Specificity 0.87 (95% CI: 0.81-0.91) (JAMA, 2019) [MEDLINE]
Upper Lip Bite Test
Technique
Easy to Perform Assessment of Patient’s Ability of Lower Incisors to Extend and Reach the Upper Lip
Clinical Efficacy
Systematic Review of Upper Lip Bite Test to Predict Difficult Intubation (JAMA, 2019) [MEDLINE]: n= 33, 559 Patients (62 High-Quality Studies)
Approximately 10% (95% CI: 8.2%-12%) of Patients were Difficult to Intubate in the Systematic Review
In Terms of Predicting Difficulty to Intubate, Grade of Class 3 on the Upper Lip Bite Test Had a Positive Likelihood Ratio of 14 (95% CI: 8.9-22) and Specificity 0.96 (95% CI: 0.93-0.97)
In Terms of Predicting Difficulty to Intubate, Shorter Hyomental Distance Had a Range of <3-5.5 cm, Positive Likelihood Ratio 6.4 (95% CI: 4.1-10), and Specificity 0.97 (95% CI: 0.94-0.98)
In Terms of Predicting Difficulty to Intubate, Retrognathia (Mandible Measuring <9 cm from the Angle of the Jaw to the Tip of the Chin or Subjectively Short) Had a Positive Likelihood Ratio 6.0 (95% CI, 3.1-11) and Specificity 0.98 (95% CI: 0.90-1.0)
In Terms of Predicting Difficulty to Intubate, Combination of Physical Findings Based on the Wilson Score Had a Positive Likelihood Ratio 9.1 (95% CI: 5.1-16) and Specificity 0.95 [95% CI: 0.90-0.98)
In Terms of Predicting Difficulty to Intubate, Modified Mallampati Score (≥3) had a Positive Likelihood Ratio 4.1 (95% CI: 3.0-5.6) and Specificity 0.87 (95% CI: 0.81-0.91)
An Abnormal Upper Lip Bite Test Raises the Probability of Difficult Intubation from 10% to >60% for the Average Risk Patient
Naguib Airway Assessment Method
Commonly Utilized in Operative Settings
Uses Measurements in an Equation to Predict Difficult Intubation
Positive = Difficult Laryngoscopy
Negative = Easy Laryngoscopy
Clinical Efficacy
Study of Diagnostic Validity of Multivariate Airway Scoring Systems to Predict Difficult Laryngoscopy (J Intl Med Res, 2016) [MEDLINE]
All Three Scoring Systems (Naguib, LEMON, and MACOCHA) Demonstrated Inconclusive Zones Which Limit Their Clinical Utility in Predicting Difficult Intubations
LEMON Airway Assessment Score
Scoring System
Look
Facial Trauma: 1 pt
Large Incisors: 1 pt
Beard/Mustache: 1 pt
Large Tongue: 1 pt
Dentition: assess for dentures, prominent maxillary incisors, broken/loose teeth, and crowns
Scars
Evaluate Using the 3-3-2 Rule
Inter-Incisor Distance <3 Fingers: 1 pt
Hyoid-Mental Distance <3 Fingers: 1 pt
Distance Between the Hyoid Bone (Just Above the Thyroid Cartilage) and Point of Chin (Mentum)
Distance from Thyroid Prominence to the Point of Chin (Mentum) with Next Extended
Thyromental Distance is Considered Important Because During Direct Laryngoscopy, the Tongue is Displaced by the Laryngoscope into the Thyromental Space
A Short Thyromental Distance Indicates Less Space for the Tongue to Be Displaced by the Laryngoscope Blade
Mallampati Airway Class/Score ≥3: 1 pt
Obstruction of Airway (Epiglottitis, Peritonsillar Abscess, Trauma, etc): 1 pt
Limited Neck Mobility (Through Flexion and Extension): 1 pt
Neck Extension May Be Limited with History of C-Spine Surgery
Presence of C-Collar Indicates No C-Spine Mobility
Neck Extension May Be limited Due to Rheumatoid Arthritis (RA) (see Rheumatoid Arthritis): neck extension during intubation in some patients with RA may result in atlanto-axial subluxation, resulting in spinal cord injury
Scoring
Maximum: 10 pts
Clinical Efficacy
Study of LEMON Score for Prediction of Difficult Airway in the Emergency Department (Emerg Med J, 2005) [MEDLINE]
LEMON Score was Able to Successfully Stratify the Risk of Intubation Difficulty in the Emergency Department
Patients with Large Incisors, a Decreased Inter-Incisor Distance, and a Decreased Thyroid to Floor of Mouth Distance were More Likely to Have a Poor Laryngoscopic View (grades 2, 3, or 4)
Study of LEMON and LEON Scores in the Emergency Department ( J Emerg Med, 2009)
The Thyroid-to-Hyoid Distance <2 Fingers was the Only Independent Variable Which Predicted Difficult Intubation
Mallampati Score was Not a Useful Tool in Predicting the Difficulty intubation in the Emergency Department, Such that “LEMON” Can Be Modified to “LEON”
Prospective Validation of the LEMON Score in the Emergency Department (Am J Emerg Med, 2015) [MEDLINE]
Type of Laryngoscope: 84% direct larynogoscope, 16% video laryngoscope
Difficult Intubation: 5.4% with direct larynogoscope, 7.4% with video laryngoscope
Sensitivity: 85.7% with direct laryngoscope, 94.9% with video laryngoscope
Specificity: 47.6% with direct laryngoscope, 40.3% with video laryngoscope
Negative Predictive Value: 98.2% with direct laryngoscope, 9% with video laryngoscope
Study of Diagnostic Validity of Multivariate Airway Scoring Systems to Predict Difficult Laryngoscopy (J Intl Med Res, 2016) [MEDLINE]
All Three Scoring Systems (Naguib, LEMON, and MACOCHA) Demonstrated Inconclusive Zones Which Limit Their Clinical Utility in Predicting Difficult Intubations
Study of the Modified LEMON Score in Patients Undergoing Intubation for Emergency Surgery for Trauma (J Emerg Surg, 2018) [MEDLINE]
Modified LEMON Score (the LEON Score, Omitting the Mallampati Score Component) was Correlated with Difficult Intubation in Adult Trauma Patients Undergoing Emergency Surgery
Systematic Review of Airway Assessment Methods to Predict Difficult Intubation (JAMA, 2019) [MEDLINE]: n= 33, 559 Patients (62 High-Quality Studies)
Approximately 10% (95% CI: 8.2%-12%) of Patients were Difficult to Intubate in the Systematic Review
In Terms of Predicting Difficulty to Intubate, Grade of Class 3 on the Upper Lip Bite Test Had a Positive Likelihood Ratio of 14 (95% CI: 8.9-22) and Specificity 0.96 (95% CI: 0.93-0.97)
In Terms of Predicting Difficulty to Intubate, Shorter Hyomental Distance Had a Range of <3-5.5 cm, Positive Likelihood Ratio 6.4 (95% CI: 4.1-10), and Specificity 0.97 (95% CI: 0.94-0.98)
In Terms of Predicting Difficulty to Intubate, Retrognathia (Mandible Measuring <9 cm from the Angle of the Jaw to the Tip of the Chin or Subjectively Short) Had a Positive Likelihood Ratio 6.0 (95% CI, 3.1-11) and Specificity 0.98 (95% CI: 0.90-1.0)
In Terms of Predicting Difficulty to Intubate, Combination of Physical Findings Based on the Wilson Score Had a Positive Likelihood Ratio 9.1 (95% CI: 5.1-16) and Specificity 0.95 [95% CI: 0.90-0.98)
In Terms of Predicting Difficulty to Intubate, Modified Mallampati Score (≥3) had a Positive Likelihood Ratio 4.1 (95% CI: 3.0-5.6) and Specificity 0.87 (95% CI: 0.81-0.91)
An Abnormal Upper Lip Bite Test Raises the Probability of Difficult Intubation from 10% to >60% for the Average Risk Patient
MACOCHA Airway Assessment Score
Scoring System (Am J Respir Crit Care Med, 2013) [MEDLINE]
MACOCHA Score Can Be Used to Predict Intubation Failure in Non-Anesthesiologist Trainees (J Crit Care, 2015) [MEDLINE]
Study of Diagnostic Validity of Multivariate Airway Scoring Systems to Predict Difficult Laryngoscopy (J Intl Med Res, 2016) [MEDLINE]
All Three Scoring Systems (Naguib, LEMON, and MACOCHA) Demonstrated Inconclusive Zones Which Limit Their Clinical Utility in Predicting Difficult Intubations
Systematic Review of Airway Assessment Methods to Predict Difficult Intubation (JAMA, 2019) [MEDLINE]: n= 33, 559 Patients (62 High-Quality Studies)
Approximately 10% (95% CI: 8.2%-12%) of Patients were Difficult to Intubate in the Systematic Review
In Terms of Predicting Difficulty to Intubate, Grade of Class 3 on the Upper Lip Bite Test Had a Positive Likelihood Ratio of 14 (95% CI: 8.9-22) and Specificity 0.96 (95% CI: 0.93-0.97)
In Terms of Predicting Difficulty to Intubate, Shorter Hyomental Distance Had a Range of <3-5.5 cm, Positive Likelihood Ratio 6.4 (95% CI: 4.1-10), and Specificity 0.97 (95% CI: 0.94-0.98)
In Terms of Predicting Difficulty to Intubate, Retrognathia (Mandible Measuring <9 cm from the Angle of the Jaw to the Tip of the Chin or Subjectively Short) Had a Positive Likelihood Ratio 6.0 (95% CI, 3.1-11) and Specificity 0.98 (95% CI: 0.90-1.0)
In Terms of Predicting Difficulty to Intubate, Combination of Physical Findings Based on the Wilson Score Had a Positive Likelihood Ratio 9.1 (95% CI: 5.1-16) and Specificity 0.95 [95% CI: 0.90-0.98)
In Terms of Predicting Difficulty to Intubate, Modified Mallampati Score (≥3) had a Positive Likelihood Ratio 4.1 (95% CI: 3.0-5.6) and Specificity 0.87 (95% CI: 0.81-0.91)
An Abnormal Upper Lip Bite Test Raises the Probability of Difficult Intubation from 10% to >60% for the Average Risk Patient
Specific Preoperative Airway Assessment of Patients with Known/Suspected Obstructive Sleep Apnea (OSA) (see Obstructive Sleep Apnea)
Recommendations (American Society of Anesthesiologists Practice Guidelines for the Perioperative Management of Patients with Obstructive Sleep Apnea 2014) (Anesthesiology, 2014) [MEDLINE]
Specific Preoperative Airway Assessment of Patients with a Potential Difficult Airway
Recommendations (2022 American Society of Anesthesiologists Practice Guidelines for Management of the Difficult Airway) (Anesthesiology, 2022) [MEDLINE]
Recommendations for Airway Evaluation
Before Initiation of Anesthetic Care/Airway Management, Airway Risk Assessment Should Be Performed by the Person(s) Responsible for Airway Management (Whenever Feasible) to Identify Patient, Medical, Surgical, Environmental, and Anesthetic Factors (Risk of Aspiration, etc) Which May Indicate the Potential for a Difficult Airway
When Available in the Patient’s Medical Record, Evaluate Demographic Information, Clinical Conditions, Diagnostic Test Findings, Patient/Family Interviews, and Questionnaire Responses
Assess Multiple Demographic and Clinical Characteristics to Determine a Patient’s Potential for a Difficult Airway or Aspiration
Before Initiation of Anesthetic Care/Airway Management, Conduct an Airway Physical Examination to Identify Physical Characteristics Which May Indicate the Potential for a Difficult Airway
Physical Examination May Include Assessment of Facial Features, Anatomical Measurements, and Landmarks
Additional Evaluation to Characterize the Likelihood or Nature of the Anticipated Airway Difficulty May Include Bedside Endoscopy, Virtual Laryngoscopy/Bronchoscopy, or Three-Dimensional Printing
Assess Multiple Airway Features to Determine a Patient’s Potential for Difficult Airway or Aspiration
Recommendations for Preparation for Difficult Airway Management
Ensure that Airway Management Equipment is Available in the Room
Ensure that a Portable Storage Unit Which Contains Specialized Equipment for Difficult Airway Management is Immediately Available
If a Difficult Airway is Known or Suspected
Ensure that a Skilled Individual is Present or Immediately Available to Assist with Airway Management (When Feasible)
Inform the Patient (or Responsible Person) of the Special Risks and Procedures Pertaining to Management of the Difficult Airway
Properly Position the Patient, Administer Supplemental Oxygen Before Initiating Management of the Difficult Airway, and Continue to Deliver Supplemental Oxygen (Whenever Feasible) throughout the Process of Difficult Airway Management (including Extubation
At a Minimum, Ensure that Monitoring According to the ASA Standards for Basic Anesthesia Monitoring is Performed Before/During/After Airway Management of All Patients
Recommendations for Anticipated Difficult Airway Management
Have a Preformulated Strategy for Management of the Anticipated Difficult Airway
Strategy Will Depend on the Anticipated Surgery, Condition of the Patient, Patient Cooperation/Consent, Patient Age, and Skills/Preferences of the Anesthesiologist
Develop a Strategy for the Following
Awake Intubation
Patient Who Can Be Adequately Ventilate, But is Difficult to Intubate
Patient Who Cannot Be Ventilated or Intubated
Patient Expected to Demonstrate Difficulty with Emergency Invasive Airway Rescue
When Appropriate, Perform Awake Intubation if the Patient is Suspected to Be a Difficult Intubation and ≥1 of the Following Apply
Patient Expected to Be Difficult to Ventilate (with Face Mask or Supraglottic Airway)
Increased Risk of Aspiration
Patient Expected to Be Intolerant of a Brief Apneic Episode
Patient Expected to Demonstrate Difficulty with Emergency Invasive Airway Rescue
The Uncooperative or Pediatric Patient May Restrict the Options for Difficult Airway Management (Particularly Options Which Involve Awake Intubation)
Airway Management in the Uncooperative or Pediatric Patient May Require an Approach (Such as Intubation Attempts After Induction of General Anesthesia) Which Might Not Be Regarded as a Primary Approach in a Cooperative Patient
Proceed with Airway Management After Induction of General Anesthesia When the Benefits are Judged to Outweigh the Risks
For Either Awake or Anesthetized Intubation, Airway Maneuvers May Be Attempted to Facilitate Intubation
Before Attempting Intubation of the Anticipated Difficult Airway, Determine the Benefit of a Noninvasive vs Invasive Approach to Airway Management
If Noninvasive Approach is Selected, Identify a Preferred Sequence of Noninvasive Airway Management Devices
If Difficulty is Encountered with a Technique, Combination Techniques May Be Used
Be Aware of the Passage of Time, the Number of Attempts, and Oxygen Saturation
Provide and Test Mask Ventilation After Each Attempt (When Feasible)
Limit the Number of Attempts at Endotracheal Intubation or Supraglottic Airway Placement to Avoid Potential Injury and Complications
If Elective Invasive Approach is Selected, Identify a Preferred Intervention
Ensure that an Invasive Airway is Performed by an Individual Trained in Invasive Airway Techniques (Whenever Possible)
If the Selected Approach Fails or is Not Feasible, Identify an Alternative Invasive Intervention
Initiate VV-ECMO When/if Appropriate and Available
Recommendations for Unanticipated and Emergency Difficult Airway Management
Call for Help
Optimize Oxygenation
When Appropriate, Refer to an Algorithm and/or Cognitive Aid
When Encountering an Unanticipated Difficult Airway
Determine the Benefit of Waking and/or Restoring Spontaneous Breathing
Determine the Benefit of a Noninvasive vs Invasive Approach to Airway Management
If a Noninvasive Approach is Selected, Identify a Preferred Sequence of Noninvasive Airway ManagementDevices to Use
If Difficulty is Encountered with Individual Techniques, Combination techniques May Be Performed
Be Aware of the Passage of Time, the Number of Attempts, and Oxygen Saturation
Provide and Test Mask Ventilation After Each Attempt (When Feasible)
Limit the Number of Attempts at Endotracheal Intubation or Supraglottic Airway Placement to Avoid Potential Injury and Complications
If an Invasive approach to the Airway is Necessary (Due to “Cannot Intubate, Cannot Ventilate” Scenario), Identify a Preferred Intervention
Ensure that an Invasive Airway is Performed by an Individual Trained in Invasive Airway Techniques (Whenever Possible)
Ensure that an Invasive Airway is Performed as Rapidly as Possible
If the Selected Invasive Approach Fails or is Not Feasible, Identify an Alternative Invasive Intervention
Initiate VV-ECMO When/if Appropriate and Available
Bag-Valve-Mask (BVM) Ventilation
General Comments
Proper Bag-Valve-Mask Ventilation Allows for Adequate Oxygenation and Ventilation, Giving the Provider Time to Prepare for a Well-Controlled Endotracheal Intubation (see Endotracheal Intubation)
Requirements for Effective Bag-Valve-Mask Ventilation
Proper Mask Seal
Upper Airway Patency
Ability to Provide the Proper Respiratory Rate, Tidal Volume, and Cadence to Achieve Ventilation
Types of Ventilation Bags
Self-Inflating Ventilation Bag (Ambu Bag)
Technique
Bag Has a Recoil Mechanism, Allowing Self-Inflation: does not require an oxygen flow to reinflate
Ambu Bag Has a One-Way Valve to Prevent Rebreathing: however, with a tight mask seal, some spontaneously breathing patients may be able to generate adequate inspiratory pressure to overcome the one-way valve
Oxygen Flows to the Patient When the Bag is Squeezed
Range of Oxygen Delivery: 95-100% FIO2 (with reservoir)
Considerations
Allows Assisted Ventilation in Combination with Supplemental Oxygen: assisted ventilation is useful for patient who may be hypoxemic in combination with hypercapnic (i.e. in type II hypoxemic, hypercapnic respiratory failure)
Should Not Use to Provide Blow By
Requires a Reservoir to Achieve Higher FIO2
Flow-Inflating Ventilation Bag (Anesthesia Bag)
Technique
Flow-Inflating Bag Provides a Constant Flow of Oxygen (When Connected to an Oxygen Source): bag requires a constant oxygen flow to remain inflated
Range of Oxygen Delivery: up to 100% FIO2
Considerations
Allows Assisted Ventilation in Combination with Supplemental Oxygen: assisted ventilation is useful for patient who may be hypoxemic in combination with hypercapnic (i.e. in type II hypoxemic, hypercapnic respiratory failure)
May Use to Provide Blow By
Requires Expertise to Use Effectively (Pediatr Emerg Care, 1997) [MEDLINE]
Technique
General Comments
Position the Mask So that the Top of the Mask is on the Bridge of the Nose and the Bottom of the Mask Covers the Mandibular Alveolar Ridge
Operator Should Not Rest Wrists or the Upper Part of the Mask on the Patients Eyes (to Avoid Inducing a Vagal Response or Causing Corneal Damage
Mask Size
Ensure that Airway Adjunct and Corners of the Mouth are Within the Mask and Allow a Proper Seal
Requires Only a Single Provider to Perform Both Mask Sealing and Bag Ventilation
Place Hand with Thumb Web Resting Against the Mask Connector Tube and Three Fingers Along the Mandible (Using Fingers to Advance the Mandible Forward)
Double-Handed Bag-Valve-Mask Ventilation Technique: generally considered the more effective method (Anesthesiology, 2010) [MEDLINE]
Requires a Second Person to Perform Bag Ventilation
Place Thumb and Index Finger on the Top of Mask and Other Three Fingers Along the Mandible (Using Fingers to Advance the Mandible Forward)
Alternately, the Provider Can Place Their Thenar Eminences on the Top of the Mask and the Other Four Fingers Along the Mandible (Using Fingers to Advance the Mandible Forward): this method may be less fatiguing and provide superior ventilation (Clin Anesth, 2013) [MEDLINE]
Respiratory Rate
Generally, the Respiratory Rate During Bag Ventilation Should Correspond to the Patient’s Expected Acid-Base Status (with Caution to Avoid High Respiratory Rates in the Setting of Hemodynamic Compromise)
During Cardiopulmonary Resuscitation (CPR), Respiratory Rate Should Be <10-12 Breaths/min to Avoid Creating Unnecessary Auto-PEEP Which May Increased Intrathoracic Pressure, Resulting in Decreased Venous Return to the Right Side of the Heart and Decreased Cardiac Output ( Circulation, 2004) [MEDLINE] (Crit Care Med, 2004) [MEDLINE]
During CPR, the Standard Compression:Ventilation Ratio of 30:2 Would Result in a Respiratory Rate of Approximately 8 Breaths/min
Tidal Volume
Generally, a Tidal Volume of 8-10 mL/kg is Adequate
During CPR, Tidal Volume of 5-6 mL/kg is Adequate, Due to Presence of Decreased Cardiac Output (Circulation, 1989) [MEDLINE]
Cricoid Pressure (Sellick’s Maneuver)
Definition
Cricoid Pressure Applied During Bag-Valve-Mask Ventilation Decrease Gastric Insufflation
Cricoid Pressure Applied During Rapid Sequence Intubation Theoretically Decreases Emesis with Aspiration
Maintain Cricoid Pressure Until the Endotracheal Tube Cuff is Inflated
Cautions
Cricoid Pressure is Frequently Applied Improperly and Inconsistently
Cricoid Pressure May Impair Lower Esophageal Sphincter Function
Cricoid Pressure May Result in Esophageal Injury
Cricoid Pressure May Result in Undesirable Movement of the Cervical Spine in Patients with Cervical Spinal Cord Injury
Cricoid Pressure May Contribute to Airway Obstruction, Even When Using a Video Laryngoscope (Ann Emerg Med, 2006) [MEDLINE] (Ann Emerg Med, 2013) [MEDLINE]
Clinical Efficacy
Review of Cricoid Pressure to Prevent Aspiration During Endotracheal Intubation (Emerg Med J, 2005) [MEDLINE]
There is Little Evidence that Cricoid Pressure Decreases the Incidence of Aspiration During Rapid Sequence Intubation
Cochrane Database Systematic Review of Cricoid Pressure During Rapid Sequence Endotracheal Intubation (Cochrane Database Syst Rev, 2015) [MEDLINE]
No Randomized Trials are Available to Evaluate the Efficacy of Cricoid Pressure During Rapid Sequence Endotracheal Intubation
Non-Randomized Trials Suggest that Cricoid Pressure is Not Required to Safely Perform Rapid Sequence Endotracheal Intubation
Recommendations
While Cricoid Pressure May Decrease Gastric Insufflation During Bag-Valve-Mask Ventilation, it is No Longer Recommended for Use During Rapid Sequence Endotracheal Intubation
Difficult Mask Ventilation
General Comments
Difficult Mask Ventilation Occurs in Approximately 5% of Adults (Anesthesiology, 2000) [MEDLINE] and (Anesthesiology, 2006) [MEDLINE]
Difficult Mask Ventilation is Associated with Difficult Intubation
Difficult Intubation Occurs in 30% of Patients with Difficult Mask Ventilation, as Compared to Only 8% of Patients without Difficult Mask Ventilation (Anesthesiology, 2000) [MEDLINE]
Difficult Mask Ventilation is Associated with a “Can’t Intubate, Can’t Ventilate” Scenario
Predictors of Difficult Mask Ventilation: the presence of two of these factors had a 72% sensitivity and 73% specificity (Anesthesiology, 2000) [MEDLINE] and (Anesthesiology, 2006) [MEDLINE]
Age >55 y/o: age is associated with increased pharyngeal resistance to airflow (from choanae to epiglottis) in men, but not in women
BMI >26 kg/m2: obesity is associated with decreased posterior airway space behind the base of the tongue, impaired airway patency during sleep, and is a risk factor for OSA
Lack of Teeth
Presence of Beard
History of Snoring
Limited Mandibular Protrusion
Etiology of Difficult Mask Ventilation (Respir Care, 2015) [MEDLINE]
Management of Difficult Bag-Valve-Mask Ventilation the Edentulous Patient
Reinsert False Teeth in the Edentulous Patient to Improve Mask Seal (Anesth Analg, 2007) [MEDLINE]
Changing Location of the Lower Edge of the Mask to Between the Lower Lip and the Alveolar Ridge May Improve Mask Seal in the Edentulous Patient (Anesthesiology, 2010) [MEDLINE]
Preparation for Intubation
Hemodynamic Optimization
Since Sedative Medications and Positive-Pressure Ventilation Can Both Induce Hypotension During and/or Soon After Endotracheal Intubation, Attention Should Be Paid to Intravenous Volume Resuscitation Prior to Intubation
In Most Cases, Preemptive Intravenous Volume Resuscitation and Vasopressors Can Be Utilized Prior to and/or During Endotracheal Intubation to Mitigate or Completely Avoid the Occurrence of Intubation-Associated Hypotension
Body Positioning for Intubation
Body Positions
Sniffing Position: classical position used for intubation
Atlanto-Occipital Extension with Head Elevation of 3-7 cm
Ramped Position
Use of Towels/Blankets to Elevate the Head and Upper Torso, Creating Horizontal Alignment of the External Auditory Meatus with the Sternal Notch
Clinical Efficacy
Comparison of Sniff and Ramped Positions for Laryngoscopic Intubation in Morbidly Obese Patients (Obes Surg, 2004) [MEDLINE]: randomized trial (n = 60)
Sniffing Position was Achieved by Placing a Firm 7 cm Cushion Under the Patient’s Head: this raised the occiput a standard distance from the table
Ramped Position was Achieved by Placing Blankets Under the Upper Body and Head to Horizontally Align the External Auditory Meatus with the Sternal Notch
Ramped Position Significantly Improved the Laryngeal View, as Compared to the Standard Sniffing Position
Study of Head-Elevated Position During Endotracheal Intubation in Decreasing Airway-Related Complications (Anesth Analg, 2016) [MEDLINE]: retrospective study (n = 528)
Back-Up, Head-Elevated Position During Endotracheal Intubation Decreased Airway-Related Complications (Aspiration, Difficult Intubation, Hypoxemia, Esophageal Intubation), as Compared to Supine Positioning
Preparation of the Endotracheal Tube (ETT)
Purposes of the Endotracheal Tube
Maintenance of Airway Patency in in Patient Who Cannot Do So Independently
Maintenance of Upper Airway Patency During Positive-Pressure Mechanical Ventilation
While Negative-Pressure Ventilation May Induce Upper Airway Collapse (Requiring an Endotracheal Tube to Maintain Airway Patency with Large Negative Airway Pressures), Maintenance of Airway Patency During Positive-Pressure Ventilation is Also Critically Important
Pulmonary Toilet
Maintenance of the Ability to Therapeutically Clear Airways (i.e. Suctioning of Secretions and Blood)
Choice of Endotracheal Tube
Standard Single-Lumen Endotracheal Tube
Rusch Endotracheal Tube
Rusch Endotracheal Tube is a Reinforced Tube
Commonly Used When Flexibility of the Endotracheal Tube is Desired without Compromise of Tube Patency (Either During Intubation or Following Intubation During a Surgical Procedure)
Commonly Used for Surgical Procedures Involving the Upper Airway, Cervical Spine, etc
Subglottic Suction Port Endotracheal Tube
Subglottic Suction Port Endotracheal Tubes are Designed to Allow Suctioning of Secretions from Above the Endotracheal Tube Cuff and Theoretically Decrease the Risk of Ventilator-Associated Pneumonia (VAP) (see Hospital-Acquired Pneumonia and Ventilator-Associated Pneumonia)
Dual-Lumen Endotracheal Tube May Be Used for Single-Lung Isolation/Ventilation (During Cardiothoracic Surgery, for the Management of Severe Hemoptysis, etc)
Structure of the Endotracheal Tube
Anatomic Relationships of the Endotracheal Tube
Physical Preparation of the Endotracheal Tube
Push Top Endotracheal Tube Connector Piece Firmly into the Endotracheal Tube: this is important since insertion of this piece deeper into the endotracheal tube after intubation can be difficult in some cases
Determine if Stylet Will Be Utilized (and if it Should Be Loaded in the Endotracheal Tube)
Standard Aluminum Stylet
Gum Elastic Bougie with Bent Tip
Stiff Metal Stylet (Glidescope Stylet, etc)
Check Endotracheal Tube Cuff Balloon for Integrity: keep the 10 mL syringe available for cuff inflation after intubation
Lubricate Endotracheal Tube Cuff: avoid lubricating endotracheal tube above the cuff, as this can make handling of the tube difficult during intubation
Assure that a Colorimetric Carbon Dioxide Detector is Present
Confirmation of Functioning Suction Set-Up
Yankauer Suction Set-Up Should Be Tested for Function: in some cases with large volumes of anticipated orla material, a second suction set-up should be prepared
Preparation of Backup Airway Management Devices and Personnel with Airway Expertise
Prior to Intubation, Other Airway Devices (Including Bronchoscope, Laryngeal Mask Airway, etc) and Personnel Should Be Readily Available, Should Difficulty Be Encountered During Intubation
Pre-Intubation Airway Assessment is Crucial to Predict the Risk of a Difficult Airway Prior to Intubation, Triggering More Robust Advance Preparation
However, Since a Difficult Intubation Can Be Encountered Unexpectedly in Some Cases, Routine Preparation of Other Equipment is Always Advisable
Confirmation of Adequate Intravenous Access and Intravenous Fluids
Ensure that Patient Has at Least Two Functional Intravenous Lines in Place
Adequate Intravenous Access is Critical to Deliver Sedative and Paralytic Medications Which are Standardly Used to Facilitate Endotracheal Intubation
Loss of Functional Intravenous Lines During the Course of Endotracheal Intubation Can Significantly Delay the Performance of Rapid Sequence Intubation, Resulting in Undesired Prolonged Bag-Valve-Mask Ventilation and Gastric Insufflation
Intravenous Fluids and Vasopressors Should Be Available to Manage Post-Intubation Hypotension
Confirmation of Preparation of Sedative and Paralytic Medications for Intubation
In Addition to Below, Additional Sedatives (Propofol Drip, etc) May Be Desired to Manage Sedation After Intubation: this is critical when a short-acting sedative (such as etomidate) is used in conjunction with a long-acting paralytic agent (such as rocuronium, etc)
Team-Oriented Approach with Protocol/Checklist/Cognitive Aids
Prospective Multicenter Study of a Bundle to Decrease Endotracheal Intubation Complications in the ICU (Intensive Care Med, 2010) [MEDLINE]: n = 244 intubations
Bundle Components
Capnography
Cricoid Pressure
Fluid Loading
Preoxygenation with Noninvasive Positive Pressure Ventilation
Preparation and Early Administration of Sedation and Vasopressor Use if Needed
Presence of two operators, rapid sequence induction
Protective Ventilation
Intubation Management Protocol Decreased Immediate Severe Life-Threatening Complications (Cardiac Arrest or Death, Severe Cardiovascular Collapse, and Hypoxemia Occurring within 60 min of Endotracheal Intubation of ICU Patients
Single-Center, Prospective Observational Trial of Team Approach, Mandatory Checklist, Use of Crew Resource Management Tactics, and Postevent Debriefing to Improve the Quality of Endotracheal Intubation by Pulmonary/Critical Care Fellows (J Intensive Care Med, 2011) [MEDLINE]: n- 101 intubations
Emergency Endotracheal Intubation Could Be Performed by Pulmonary/Critical Care Fellows with Safety Comparable to Other Providers
Literature Review of Cognitive Aids in the Assistance of Anesthetic Management (Anesth Analg, 2013) [MEDLINE]
Cognitive Aids are Prompts (Posters, Flowcharts, Checklists, or Mnemonics) Designed to Assist Users Complete a Task or Series of Tasks _ Ten Studies Using Simulation Suggested that Technical Performance Improved with the Use of Cognitive Aids in Some Anesthetic Emergencies (Malignant Hyperthermia, Cardiopulmonary Resuscitation, and Airway Management)
Cognitive Aids Would Benefit from More Extensive Simulation-Based Usability Testing Before Use
Study of Implementation of a Difficult Airway Response Team (DART) at the Johns Hopkins Hospital (Anesth Analg, 2015) [MEDLINE]
DART is a Comprehensive Program for Improving Difficult Airway Management
Between July, 2008-June, 2013, DART Managed 360 Adult Difficult Airway Events, Comprising 8% of All Code Blue Activations
Predisposing Patient Factors Included BMI >40, History of Head and Neck Tumor, Prior Difficult Intubation, Cervical Spine Injury, Airway Edema, Airway Bleeding, and Previous or Current Tracheostomy
There Were No Airway Management Related Deaths, Sentinel Events, or Malpractice Claims in Adult Patients Managed by DART
Study of the Vortex Tool for Emergency Airway Management in “Can’t Intubate, Can’t Oxygenate” (CICO) Scenarios (Br J Anaesth, 2016) [MEDLINE]
The Vortex is Flexible Enough for the Same Tool to Be Applied to Any Circumstance in which Airway Management Takes Place, Independent of Context, Patient Type, or the Intended Airway Device
Multicenter Randomized Trial of a Checklist for Endotracheal Intubation of Critically Ill Adults (Chest, 2018) [MEDLINE]: n = 262
The Verbal Performance of a Written, Preprocedure Checklist Did Not Increase the Lowest Arterial Oxygen Saturation or Lowest Systolic Blood Pressure During Endotracheal Intubation of Critically Ill Adults, as Compared to Usual Care
Comprehensive Systematic Review of Randomized Trials for Endotracheal Intubation in Critically Ill Patients (Crit Care, 2018) [MEDLINE]
No Effect was Found for Use of a Pre-Intubation Checklist (Although Only 1 Trial was Reviewed)
Review of Difficult Airway Management Team (DART Experience at the Johns Hopkins Hospital (Crit Care Clin, 2018) [MEDLINE]
Article Details the Lessons Learned and Recommendations for Initiating a DART Program
Study of Simulation-Based Airway Management Training of Critical Care Fellows Using a Checklist (Chest 2020) [MEDLINE]
Simulation-Based Airway Management Training of Early Critical Care Fellows (Using a Checklist) Transferred Well to Real-Life Critical Care Airway Management Skills Later in Fellowship
Intubation Techniques
Rapid Sequence Intubation (RSI)
Definition and Background
Definition of Rapid Sequence Intubation: period of preoxygenation, folllowed by the nearly simultaneous administration of a sedative and paralytic agent to facilitate rapid and effective endotracheal intubation (with a minimal risk of aspiration)
RSI is the Most Common Emergency Intubation Technique in a Patient Who is Not Anticipated to Have a Difficult Airway: approximately 85% of first endotracheal intubation attempts in emergency departments are performed using RSI (Ann Emerg Med, 2015) [MEDLINE]
Clinical Efficacy
RSI Has Been Demonstrated to Decrease Procedure-Related Complications and Increase the Probability of First-Pass Endotracheal Intubation Success (Crit Care Med, 2012) [MEDLINE] (Ann Am Thorac Soc, 2015) [MEDLINE] (Int J Emerg Med, 2017)[MEDLINE]
RSI Has Been Demonstrated to Have High First-Pass Endotracheal Intubation Success Rates (90%) with Video Laryngoscopy in Patients with Anticipated Difficult Airways: 11% of non-arrest patients had a predicted difficult airway in this study and none required a surgical airway ( J Emerg Med, 2017) [MEDLINE]
Physiologic Basis of Rapid Sequence Intubation
RSI is Based Upon the Observation that, After Preoxygenation, an Average 70 kg Adult Will Maintain SaO2 >90% for 8 min During Apnea (Anesthesiology, 1997) [MEDLINE]
Importantly, Even with Adequate Preoxygenation, this Period of Time is <3 min in Critically Ill, Obese, and Third Trimester Pregnant Patients
This Period of Time is <4 min in Children
Preoxygenation (with the Highest Possible Oxygen Concentration for a Minimum of 3 min) Replaces Nitrogen and Other Gases in the Functional Residual Capacity, Creating an Oxygen Reservoir Which is Depleted During the Subsequent RSI Apneic Period (Anesth Analg, 2017) [MEDLINE]
Importantly, in its Pure Form, RSI Utilizes an Apneic Period Following Administration of Pharmacologic Sedation/Paralytic (Up to the Point of Endotracheal Tube Placement): bag ventilation is avoided during this period, if possible, to avoid gastric insufflation (which may result in aspiration)
Cautions
Since RSI Utilizes the Monitoring of Oxygen Saturation During Apnea, Finger Probe Pulse Oximetry May Lag Behind that of the Central Arterial Circulation in Critically Ill Patients (Can J Anaesth, 1992) [MEDLINE]: for this reason, pulse oximetry must be used with judicious caution during RSI
In Patients with Right-to-Left Shunt (Usually Intrapulmonary Shunt Resulting from Pneumonia, ARDS, etc), Standard Attempts at Preoxygenation May Be Ineffective: these patients may require positive-pressure ventilation with PEEP to promote alveolar recruitment and facilitate adequate preoxygenation
Bag-Valve Mask Ventilation, Noninvasive Positive-Pressure Ventilation, or High-Flow Nasal Cannula Can Be Used to Facilitate Prexoygenation in this Setting
Relative Contraindications to Rapid-Sequence Intubation
Anticipated Difficult Intubation (Especially if Rescue is Anticipated to Be Difficult or Impossible)
Inability to Tolerate Apneic Period During RSI (Due to Severe Hypoxemia, Acidosis, etc)
Seven P’s of Rapid Sequence Intubation
Preparation: 10 min before intubation
Preoxygenation: 5 min before intubation
Pre-Intubation Optimization: 3 min before intubation
Paralysis with Induction: induction
Protection: 30 sec after induction
Placement (Intubation): 45 sec after induction
Post-Intubation Management: 60 sec after induction
Physiologic Basis of Rapid Sequence Intubation
Rapid Sequence Intubation is Based Upon the Observation that, After Preoxygenation, an Average 70 kg Adult Will Maintain SaO2 >90% for 8 min During Apnea (Anesthesiology, 1997) [MEDLINE]
Importantly, Even with Adequate Preoxygenation, this Period of Time is <3 min in Critically Ill, Obese, and Third Trimester Pregnant Patients
This Period of Time is <4 min in Children
Preoxygenation (with the Highest Possible Oxygen Concentration for a Minimum of 3 min) Replaces Nitrogen and Other Gases in the Functional Residual Capacity of the Lung, Creating an Oxygen Reservoir Which is Subsequently Depleted During the Subsequent Rapid Sequence Intubation Apneic Period (Anesth Analg, 2017) [MEDLINE]
Since Rapid Sequence Intubation Utilizes the Monitoring of Oxygen Saturation Using Finger Probe Pulse Oximetry During Apnea, Pulse Oximetry Readings May Lag Behind that of the Central Arterial Circulation in Critically Ill Patients (Can J Anaesth, 1992) [MEDLINE]
Consequently, Pulse Oximetry Must Be Used Judiciously During Rapid Sequence Intubation
Because Obesity is Characterized by Increased Oxygen Consumption and Increased Carbon Dioxide Production, the Time to Desaturation (and the “Safe Apnea Period” During Rapid Sequence Intubation) are Decreased (Anesthesiology, 1997) [MEDLINE]
Preoxygenation Technique
Methods to Increase the Reservoir Size During Preoxygenation
Use of Bag-Valve-Mask Ventilation or Noninvasive Positive-Pressure Ventilation, Both of Which Increase the Mean Airway Pressure
Use of 20 Degree Head-Up Patient Positioning, Which Decreases Dependent Atelectasis (Anaesthesia, 2005) [MEDLINE]
Preoxygenation Techniques Based on Patient Type
Patient with Adequate Spontaneous Ventilation and Cooperative
Bag-Valve-Mask Ventilation with Oxygen at 15 L/min
Squeezing the Bag is Not Necessary, But a Tight Mask Seal Must Be Maintained to Ensure a High FIO2
If the Time is Critically Short and the Bag is Squeezed, Eight Vital Capacity Breaths Can Achieve Adequate Preoxygenation in <1 min
Patient with Adequate Spontaneous Ventilation and Uncooperative/Intolerant of Bag-Valve-Mask Ventilation
Non-Rebreather Mask with Flush Rate Oxygen (≥50 L/min): note that standard 15 L/minflow rates are inadequate for preoxygenation due to entrainment of room air (and decrease in the effective FIO2)
High-Flow Nasal Cannula: can also be considered
Patient with Inadequate Spontaneous Ventilation
Bag-Valve-Mask Ventilation with Oxygen at 15 L/min (Synchronized with Patient’s Respiratory Efforts): avoid pressure >20 cm H2O to minimize the degree of gastric insufflation
In its Pure Form, Rapid Sequence Intubation Utilizes Administration of Pharmacologic Sedation (Induction) and Paralysis, Followed by an Apneic Period without Bag-Valve-Mask Ventilation Up to the Point of Endotracheal Tube Placement
Bag-Valve-Mask Ventilation is Avoided, if Possible, to Avoid Gastric Insufflation (Which May Result in Aspiration)
However, In Patients with Right-to-Left Shunt (Usually Intrapulmonary Shunt Resulting from Pneumonia, ARDS, etc), Standard Attempts at Preoxygenation May Be Ineffective
These Patients May Require Positive-Pressure Ventilation with PEEP to Promote Alveolar Recruitment and Facilitate Adequate Preoxygenation
Bag-Valve Mask Ventilation, Noninvasive Positive-Pressure Ventilation, or High-Flow Nasal Cannula Can Be Used to Facilitate Prexoygenation in this Setting
Continuous Passive Oxygenation During Apnea (“Apneic Oxygenation”)
Continuous Passive Oxygenation Can Be Used During the Rapid Sequence Intubation Apneic Period for Patients Who Cannot Tolerate the Apneic Period without Developing Hypoxemia
Continuous Passive Oxygenation Slows Depletion of the Oxygen Reservoir Created During Preoxygenation
Apneic Oxygenation Can Potentially Induce Worsening Hypercapnia in Patients with Chronic Hypoventilation (in this Setting, Predominantly Due to the Worsening of V/Q Mismatch)
The Resulting Hypercapnia Can Be Deleterious in Specific Patient Populations, Such as Those with Increased Intracranial Pressure, Metabolic Acidosis, or Pulmonary Hypertension
Continuous Passive Oxygenation Techniques
High-Flow Nasal Cannula (HFNC)
Standard Nasal Cannula (at a High Flow Rate): at flow rate ≥15 L/min
Clinical Efficacy-Preoxygenation and Continuous Passive Oxygenation During Apnea (“Apneic Oxygenation”)
Study of Nasopharyngeal Apneic Oxygenation Using the Four Breath Technique in Surgical Patients (Anaesthesia, 2006) [MEDLINE]
Apneic Oxygenation (Following Preoxygenation Using the Four Breath Technique) Delayed the Onset of Oxygen Desaturation During Apnea
Study of Apneic Oxygenation in During Simulated Laryngoscopy in Obese Patients (J Clin Anesth, 2010) [MEDLINE]
Nasal Apneic Oxygenation Improved the Frequency/Duration of SpO2 ≥95% and Increased the Minimal SpO2 During Prolonged Laryngoscopy in Obese Patients
Transnasal Humidified Rapid-Insufflation Ventilatory Exchange (THRIVE) Increases Apnea Time During Endotracheal Intubation (Anaesthesia, 2015) [MEDLINE]
High-Nasal Cannula Oxygenation (During Preoxygenation and Continuing as Post-Oxygenation During Intravenous Induction of Anaesthesia and Neuromuscular Blockade Until Airway was Secured) Increases the Apnea Time During Endotracheal Intubation
Proposed Mechanism: combines the benefits of classical apneic oxygenation with continuous positive airway pressure and gaseous exchange through flow-dependent deadspace flushing
French PREOXYFLOW Multicenter Randomized Trial of High-Flow Nasal Cannula in Hypoxemic Patients Undergoing Intubation (Intensive Care Med, 2015) [MEDLINE]: multicenter, randomized opne-labelled, controlled trial in 6 French ICU’s (n = 124)
In Terms of the Lowest Level of Oxygen Desaturation, High-Flow Nasal Cannula (Maintained Throughout the Procedure) was Comparable to High-Flow Face Mask Preoxygenation (Removed at End of General Anesthesia Induction)
No Differences were Observed in Difficult Intubations, Ventilator-Free Days, intubation-Related Events, or Mortality Rate
Trial of High-Flow Nasal Cannula During Endotracheal Intubation in ICU Patients (Crit Care Med, 2015) [MEDLINE]: n = 101
High-Flow Nasal Cannula Oxygen Significantly Improved Preoxygenation and Reduced the Prevalence of Severe Hypoxemia, as Compared to Non-Rebreathing Bag Reservoir Facemask Oxygen
Australian Study of Apneic Oxygenation in Helicopter Emergency Service (Ann Emerg Med, 2015) [MEDLINE]
Apneic Oxygenation Decreased the Incidence of Oxygen Desaturation in Patients Undergoing Rapid Sequence Intubation
Study of Apneic Oxygenation in Adult Patients the Emergency Department (Acad Emerg Med, 2016) [MEDLINE]
Apneic Oxygenation Increased First-Pass Intubation Success without Hypoxemia
Randomized Trial of Apneic Oxygenation During Intubation in Critically Ill Adult Patients in the Medical ICU (Am J Respir Crit Care Med, 2016) [MEDLINE]: n= 150
Apneic Oxygenation Had No Effect on the Lowest Oxygen Saturation in Critically Ill Patients
German Randomized Trial of Flow Nasal Cannula Versus Bag-Valve-Mask for Preoxygenation Before Intubation in Subjects With Hypoxemic Respiratory Failure (Respir Care, 2016) [MEDLINE]: n = 40
No Significant Difference in the Mean Lowest Oxygen Saturation During intubation Between the High-Flow Nasal Cannula Group and the Bag-Valve-Mask-Ventilation Group in Patients with Mild-Moderate Hypoxemic Respiratory Failure
However, On Continuous Monitoring, There was a Significant Decrease in Oxygen Saturation During the Apnea Phase Before Intubation in the Bag-Valve-Mask-Ventilation Group, which was Not Observed in the High-Flow Nasal Cannula Group
French OPTINIV Trial of High-Flow Nasal Cannula Combined with Noninvasive Positive-Pressure Ventilation vs Noninvasive Positive-Pressure Ventilation Alone for Preoxygenation Prior to Intubation (Intensive Care Med, 2016) [MEDLINE]: single-center, blinded, randomized trial
Use of Combined High-Flow Nasal Cannula and Noninvasive Positive-Pressure Ventilation for Preoxygenation Prior to Intubation was More Effective in Decreasing Oxygen Desaturation, as Compared to Noninvasive Positive-Pressure Ventilation Alone
Trial of Apneic Oxygenation During Rapid Sequence Intubation in the Emergency Department (Acad Emerg Med, 2016) [MEDLINE]
Apneic Oxygenation During RSI Increased the First Pass Success (without Hypoxemia) Rate: defined as successful intubation with SaO2 remaining ≥90%
Randomized Trial of Apneic Oxygenation During Intubation in a Medical ICU (Am J Respir Crit Care Med, 2016) [MEDLINE]: n = 150
Apneic Oxygenation with High-Flow Nasal Cannula (15 L/min) During Intubation Did Not Increase the Lowest SaO2, as Compared to Usual Care
Systematic Review and Meta-Analysis of Support Techniques to Prevent Oxygen Desaturation in Critically Ill Patients Requiring Endotracheal Intubation ( J Crit Care, 2017) [MEDLINE]
Apneic Oxygenation was Significantly Associated with Higher Minimum Oxygen Saturation During Intubation, as Compared to No Apneic Oxygenation: but there were no significant differences in severe hypoxemia and intubation related-complications
Further Study is Required to Evaluate the Role of Noninvasive Positive-Pressure Ventilation (NIPPV) and High-Flow Nasal Cannula (HFNC)
Systematic Review/Meta-Analysis of Apneic Oxygenation During Emergency Intubation (Am J Emerg Med, 2017) [MEDLINE]
Apneic Oxygenation Significantly Decreased the Incidence of Hypoxemia During Emergency Intubation
Systematic Review/Meta-Analysis of Apneic Oxygenation (J Crit Care, 2017) [MEDLINE]
In Patients Being Intubated for Any Indication Other than Respiratory Failure, Apneic Oxygenation at Any Flow Rate >15 L/min Decreased the Incidence of Desaturation (<90%) and Critical Desaturation (<80%)
Further Trials are Required, Given the Degree of Heterogeneity in Outcomes and Subgroup Analyses
Systematic Review/Meta-Analysis of Apneic Oxygenation (Ann Emerg Med, 2017 [MEDLINE]
Apneic Oxygenation Increased Peri-Intubation Oxygen Saturation, Decreased the Rate of Hypoxemia, and Increased First-Pass Success Rate
Randomized ENDAO Trial of Apneic Oxygenation During Rapid Sequence Intubation in the Emergency Department (Acad Emerg Med, 2017) [MEDLINE]: n = 200
Apneic Oxygenation Had No Effect on the Lowest Mean Oxygen Saturation
However, All Patients were Intubated within 120 sec in this Trial, Likely Diluting Out Any Effect that Apneic Oxygenation Might Have Had
Study of Risk Factors for and Prediction of Hypoxemia During Endotracheal Intubation of Critically Ill Adults (Ann Am Thorac Soc, 2018) [MEDLINE]: n = 426
Predictors of Severe Hypoxemia During Endotracheal Intubation of Critically Ill Adult
Hypoxemic Respiratory Failure as Indication for Intubation (Odds Ratio 2.70; 95% CI: 1.58-4.60)
Lower Oxygen Saturation at Induction (Odds Ratio 0.92 Per 1% Increase; 95% CI: 0.89-0.96 Per 1% Increase)
Younger Age (Odds Ratio 0.97 Per 1-Year Increase in Age; 95% CI: 0.95-0.99 Per 1-Year Increase in Age)
Higher Body Mass Index (Odds Ratio 1.03 Per 1 kg/m2; 95% CI: 1.00-1.06 Per 1 kg/m2)
Race (Odds Ratio 4.58 for White vs Black; 95% CI, 1.97-10.67; Odds Ratio 4.47 for Other vs Black; 95% CI: 1.19-16.84)
Operator with <100 Prior Intubations (Odds Ratio 2.83; 95% CI: 1.37-5.85)
Comprehensive Systematic Review of Randomized Trials for Endotracheal Intubation in Critically Ill Patients (Crit Care, 2018) [MEDLINE]: n = 22 trials
Analyzed 1 Trial Using Pre-Procedure Checklist, 6 Trials of Preoxygenation or Apneic Oxygenation, 3 Trials of Sedatives, 1 Trial of Neuromuscular Blocking Agents, 1 Trial of Patient Positioning, 9 Trials of Video Laryngoscopy, and 1 Trial of Post-Intubation Lung Recruitment
Preoxygenation with Noninvasive Positive-Pressure Ventilation and/or High-Flow Nasal Cannula Before Endotracheal Intubation was Beneficial
Post-Intubation Lung Recruitment Maneuvers May Increase Post-Intubation Oxygenation
No Effect was Found for Use of a Pre-Intubation Checklist, Apneic Oxygenation (on Oxygenation and Hemodynamics), Video Laryngoscopy (on Number and Length of Intubation Attempts), Sedatives and Neuromuscular Blockers (on Hemodynamics)
Video Laryngoscopy was Associated with Severe Adverse Effects in Multiple Trials
Ramped Position Increased the Number of Intubation Attempts
Thiopental Had Negative Hemodynamic Effects
Multicenter, Randomized PreVent Trial of Bag-Valve-Mask Ventilation During Endotracheal Intubation in Critically Ill Patients (NEJM, 2019) [MEDLINE]: n = 401 (7 intensive care units in the US)
Bag-Valve-Mask Ventilation During Endotracheal Intubation Resulted in Improved Oxygenation, as Compared to Apnea Between Induction and Laryngoscopy
Operator-Reported Aspiration Occurred During 2.5% of Intubations in the Bag-Valve-Mask Ventilation Group and During 4.0% of Intubations in the No-Ventilation Group (P = 0.41)
Incidence of New Opacity on Chest X-Ray in the 48 hrs After Endotracheal Intubation was 16.4% in the Bag-Valve-Mask Ventilation Group and 14.8% in the No Ventilation Group (P = 0.73)
Randomized PROTRACH Trial of Nasal High-Flow Preoxygenation for Endotracheal Intubation in the Critically Ill Patient (Intensive Care Med, 2019) [MEDLINE]: n = 192 randomized, n = 184 in intent-to-treat analysis
Compared with Standard Bag-Valve-Mask Oxygenation, Preoxygenation with High-Flow Nasal Cannula Did Not improve the Lowest Oxygen Saturation During Intubation in the Non-Severely Hypoxemic Patients, But Led to a Decrease in Intubation-Related Adverse Events
Cricoid Pressure (Sellick’s Maneuver)
Definition
Cricoid Pressure Applied During Bag-Valve-Mask Ventilation Decrease Gastric Insufflation
Cricoid Pressure Applied During Rapid Sequence Intubation (and Maintained Until the Endotracheal Tube Cuff is Inflated) Theoretically Decreases Emesis with Aspiration
Cautions
Cricoid Pressure is Frequently Applied Improperly and Inconsistently
Cricoid Pressure May Impair Lower Esophageal Sphincter Function
Cricoid Pressure May Result in Esophageal Injury
Cricoid Pressure May Result in Undesirable Movement of the Cervical Spine in Patients with Cervical Spinal Cord Injury
Cricoid Pressure May Contribute to Airway Obstruction, Even When Using a Video Laryngoscope (Ann Emerg Med, 2006) [MEDLINE] (Ann Emerg Med, 2013) [MEDLINE]
Clinical Efficacy
Review of Cricoid Pressure to Prevent Aspiration During Endotracheal Intubation (Emerg Med J, 2005) [MEDLINE]
There is Little Evidence that Cricoid Pressure Decreases the Incidence of Aspiration During Rapid Sequence Intubation
Cadaver Study of Airway Maneuvers During Laryngoscopy (Ann Emerg Med, 2006) [MEDLINE]
Bimanual Laryngoscopy Improved the Laryngoscopic View, as Compared to Cricoid Pressure, BURP, and No Manipulation
Cricoid Pressure and BURP Frequently Worsen the Laryngoscopic View
Anatomic MRI Study of the Effects of Cricoid Pressure During Endotracheal Intubation (Anesth Analg, 2009) [MEDLINE]
Cricoid Pressure Results in Compression of the Postcricoid Hypopharynx (Hypopharynx and Cricoid Ring Move Together as an Anatomic Unit)
The Location and Movement of the Esophagus is Irrelevant to the Efficiency of Cricoid Pressure in Regard to Prevention of Gastric Regurgitation into the Pharynx
Compression of the Esophagus Occurs with Midline and Lateral Displacement of the Cricoid Cartilage Relative to the Underlying Vertebral Body
Intubation Bundles Can Decrease the Incidence of Post-Intubation Adverse Effects/Complications in the Intensive Care Unit (Intensive Care Med, 2010) [MEDLINE]: n = 244
Bundle Components
Capnography
Cricoid Pressure
Intravenous Fluid Loading
Preoxygenation with Noninvasive Positive-Pressure Ventilation
Preparation and Early Administration of Sedation
Presence of Two Operators
Protective Ventilation
Rapid Sequence Induction
Vasopressor Use (If Required)
Observational Study of Identification of the Cricothyroid Membrane in Female Subjects Using Palpation (Anesth Analg, 2012) [MEDLINE]
Misidentification of the Cricothyroid Membrane in Female Patients is Common and its Localization is Less Precise in Those Who are Obese
Cochrane Database Systematic Review of Cricoid Pressure During Rapid Sequence Endotracheal Intubation (Cochrane Database Syst Rev, 2015) [MEDLINE]
No Randomized Trials are Available to Evaluate the Efficacy of Cricoid Pressure During Rapid Sequence Endotracheal Intubation
Non-Randomized Trials Suggest that Cricoid Pressure is Not Required to Safely Perform Rapid Sequence Endotracheal Intubation
Randomized IRIS Trial of Cricoid Pressure in Operating Room Rapid Sequence Intubation (JAMA Surg, 2019) [MEDLINE]: n = 3472
Cricoid Pressure Had No Clinical Benefit in Preventing Aspiration, as Compared to Sham Cricoid Procedure
Secondary End Points (Pneumonia, Length of Stay, Mortality) Were Similar Between the Two Groups
Intubation Time was Longer in the Cricoid Pressure Group
Recommendations
While Cricoid Pressure May Decrease Gastric Insufflation During Bag-Valve-Mask Ventilation, it is No Longer Recommended for Use During Rapid Sequence Endotracheal Intubation
Backward-Upward-Rightward (BURP) Maneuver
Definition:
Backward-Upward-Rightward Movement of Larynx by Manipulating the Thyroid Cartilage
Clinical Efficacy
Cadaver Study of Airway Maneuvers During Laryngoscopy (Ann Emerg Med, 2006) [MEDLINE]
Bimanual Laryngoscopy Improved the Laryngoscopic View, as Compared to Cricoid Pressure, BURP, and No Manipulation
Cricoid Pressure and BURP Frequently Worsen the Laryngoscopic View
Mandibular Advancement
May Improve the Laryngoscopic View
Clinical Efficacy
Mandibular Advancement May Improve the Laryngoscopic View During Intubation Performed by Inexperienced Operators (Anesthesiology, 2004) [MEDLINE]
Gum Elastic Bougie
Clinical Efficacy
Randomized Trial of Gum Elastic Bougie vs Endotracheal Tube and Stylet in Difficult Emergency Intubation in the Emergency Department (JAMA, 2018) [MEDLINE]
Gum Elastic Bougie Increased First-Pass Success Rate in Emergency Difficult Intubation, as Compared to Endotracheal Tube and Stylet
Induction and Paralytic Medications for Rapid Sequence Intubation
Video Laryngoscopy is Being Increasingly Used (27% of Cases) as the First Emergency Adult Endotracheal Intubation Attempt Method in Emergency Departments: presumably replacing direct laryngoscopy (Ann Emerg Med, 2015) [MEDLINE]
Advantages
Video Laryngoscope Provides a Superior View, as Compared to Direct Laryngoscopy
Video Laryngoscope Results in Less Cervical Spinal Motion, as Compared to Direct Laryngoscopy: beneficial in patients with unsecured cervical spinal cord injury (J Emerg Med, 2013) [MEDLINE]
Clinical Efficacy
Systematic Review/Meta-Analysis of Video Laryngoscopic vs Direct Laryngoscopic Endotracheal Intubation (Intensive Care Med, 2014) [MEDLINE]: 9 trials (n = 2133) comparing direct laryngoscopic vs video laryngoscopic intubaton in the ICU
Compared to Direct Laryngoscopy, Video Laryngoscopy Reduced the Risk of Difficult Orotracheal Intubation [OR 0.29 (95% confidence interval (CI) 0.20-0.44, p < 0.001)], Cormack 3/4 Grade Airways [OR 0.26 (95% CI 0.17-0.41, p < 0.001)], and Esophageal Intubation [0.14 (95% CI 0.02-0.81, p = 0.03)]
Compared to Direct Laryngoscopy, Video Laryngoscopy Increased the First-Attempt Success Rate [OR 2.07 (95% CI 1.35-3.16, p < 0.001)]
No Statistically Significant Difference was Found for Severe Hypoxemia, Severe Cardiovascular Collapse, or Airway Injury
Randomized Trial of Glidescope Video Laryngoscopy (Crit Care Med, 2015) [MEDLINE]
Glidescope Video Laryngoscopy Improved First-Pass Intubation Success Rates for Urgent Endotracheal Intubation Performed by Pulmonary and Critical Care Medicine Fellow, as Compared to Direct Laryngoscopy
Emergency Department Study of Combined Rapid Sequence Intubation and Video Laryngoscopy ( J Emerg Med, 2017) [MEDLINE]
Approximately 11% of Patients (n = 50) Had a Predicted Difficult Airway
Rapid Sequence Intubation was Demonstrated to Have High First-Pass Endotracheal Intubation Success Rates (90%) with Video Laryngoscopy in Patients with Anticipated Difficult Airways
None of the Patients with Difficult Airway Required Placement of a Surgical Airway
Consensus Guideline Recommendations to Prevent Unrecognized Esophageal Intubation from the Project for Universal Management of Airways and International Airway Societies (Anaesthesia, 2022) [MEDLINE]
Exhaled Carbon Dioxide Monitoring and Pulse Oximetry Should Be Available and Used for All Episodes of Airway Management
Routine Use of Video Laryngoscopy is Recommended Whenever Feasible
At Each Attempt at Laryngoscopy, the Airway Operator Should Verbalize the View Obtained
The Airway Operator and Assistant Should Each Verbalize Whether Sustained Exhaled Carbon Dioxide and Adequate Oxygen Saturation are Present
Inability to Detect Sustained Exhaled Carbon Dioxide Requires Esophageal intubation to Be Actively Excluded
The Default Response to the Failure to Satisfy the Criteria for Sustained Exhaled Carbon Dioxide Should Be to Remove the Tube and Attempt Ventilation Using a Facemask or Supraglottic Airway
If Immediate Tube Removal is Not Undertaken, Actively Exclude Esophageal Intubation
Repeat Laryngoscopy, Flexible Bronchoscopy, Ultrasound and Use of an Esophageal Detector Device are Valid Techniques
Clinical Examination Should Not Be Used to Exclude Esophageal intubation
Endotracheal Tube Removal Should Be Undertaken if Any of the Following are Present
Esophageal Placement Cannot Be Excluded
Sustained Exhaled Carbon Dioxide Cannot Be Restored
Oxygen Saturation Deteriorates at Any Point Before Restoring Sustained Exhaled Carbon Dioxide
Actions Should Be Taken to Standardize and Improve the Distinctiveness of Variables on Monitor Displays
Interprofessional Education Programs Addressing the Technical and Team Aspects of Task Performance Should Be Undertaken to Implement These Guidelines
Cormack-Lehane (C-L) View of Glottis
Grade I: full view of glottis
Grade II: partial glottic view
Grade III: minimal glottic view
Grade IV: no view of glottis
Lighted Stylet (Trachlight, etc)
Lighted Stylet Can Be Used for Management of the Difficult Anterior Airway, Where Airway Anatomy is Not Distorted
Device Transilluminates the Glottis Through the Soft Tissues of the Neck
Device Requires Training to Become Proficient with its Use: typically 10-20 intubations are required before proficiency is attained
Hemodynamic Responses with Lighted Stylet are Similar to that with Direct/Video Laryngoscopy
Advantages
Ability to Intubate When the Glottis Cannot Be Visualized Using Direct Laryngoscopy
Decreased Pharyngeal Trauma, as Compared to Direct Laryngoscopy
Produces Less Cervical Spinal Motion than Direct/Video Laryngoscopy: beneficial in patients with cervical spinal cord injury
Disadvantages
Cannot Be Used with Any Airway Anatomic Distortion (Such as Trauma, Tumor, Airway Foreign Body, etc)
Optical Style Uses a Fiberoptic or Video Camera in the Distal End of a Metal Stylet
Stylet Can Be Rigid, Flexible, and/or Directable (Similar to a Bronchoscope)
Disadvantages
Less Useful in the Presence of Any Obstructing Debris in the Airway (Such as Blood, Vomit, Secretions, etc)
Delayed Sequence Intubation (DSI)
Clinical Efficacy
Prospective Trial of Delayed Sequence Intubation in Patients with Delirium (Ann Emerg Med, 2015) [MEDLINE]
Dissociative Dose of Ketamine, Allowing Preoxygenation with High-Flow Nonrebreather Mask or Noninvasive Positive-Pressure Ventilation (NIPPV), Followed by Rapid Sequence Intubation was Safe and Effective
“Awake” Direct Laryngoscopic Intubation
Definition
Definition of Awake Intubation: use of topical anesthesia with light sedation (but without the use of a paralytic agent)
Awake Fiberoptic Intubation is Successful in 88-100% of Difficult Airway Patients (Category B3-B Evidence) (American Society of Anesthesiologists Task Force on Management of the Difficult Airway; Anesthesiology, 2013) [MEDLINE]
Extension of Apnea Time During Endotracheal Intubation
Clinical Efficacy
High-Flow Nasal Cannula May Be Used to Facilitate Oxygenation During Fiberoptic Intubation (Chest, 2015) [MEDLINE]
Nasotracheal Intubation
Technique
Disadvantages
Higher Incidence of Maxillary Sinusitis
Confirmation of Endotracheal Tube (ETT) Placement
Auscultation
Technique
Auscultation Over Bilateral Lung Fields and Auscultation Over the Epigastric Area: note that auscultation over the lung field alone is inadequate to confirm endotracheal tube placement (epigastric auscultation is additionally required to confirm a lack of breath sounds in that location)
Clinical Efficacy
Auscultation Alone Mistakenly Identifies Location of the Endotracheal Tube in 16% of Cases (Anesth Analg, 1986) [MEDLINE]
Observation of Chest Wall Movement is an Unreliable Means of Confirming Endotracheal Tube Placement, as Chest Wall Movement May Occur in Esophageal Intubation (Anaesth Intensive Care, 1980) [MEDLINE]
Single-View (Antero-Posterior) CXR Cannot Reliably Confirm Endotracheal Intubation: although it is usually obtained to determine the location of the distal tip of the endotracheal tube
Condensation in Endotracheal Tube (“Fogging”)
Clinical Efficacy
Observation of Condensation (Fogging) in the Endotracheal Tube is an Unreliable Means of Confirming Endotracheal Tube Placement, as Condensation Occurs in the Endotracheal Tube in 83% of Esophageal Intubations (Ann Emerg Med, 1998) [MEDLINE]
Endotracheal Introducer (Eschmann Introducer or Gum Elastic Bougie)
Technique
Bougie is Inserted and Advanced, Feeling the “Clicks” of the Tracheal Rings
Sensitivity of Ring Clicks in the Detection of Endotracheal Intubation: 95%
End-Tidal Carbon Dioxide Detection
General Comments
End-Tidal Carbon Dioxide Detection is Most Accurate Means of Confirming Endotracheal Tube Placement in the Non-Cardiac Arrest Patient: end-tidal carbon dioxide detection is a standard of care practice to confirm appropriate endotracheal intubation
In the Setting of Cardiac Arrest (without a Detectable Pulse), Gas Exchange in the Lungs is Markedly Decreased and Carbon Dioxide May Not Be Detectable Despite Appropriate Endotracheal Tube Positioning in the Trachea (Crit Care Med, 1985) [MEDLINE]
However, the Detection of Carbon Dioxide Which Persists for 6 Breaths in the Cardiac Arrest Patient Indicates Appropriate Endotracheal Tube Positioning in the Trachea
Colorimetric Carbon Dioxide Indicator
Principle/Technique: colorimetric carbon dioxide indicators use use sulfonephthalein-impregnated pH-sensitive (litmus) filter paper as an indicator which tidally changes (breath by breath) from purple to yellow in the presence of exhaled carbon dioxide
Easy CAP II (Medtronic)
A Range Corresponds to ETCO2 <0.5%: dark tan-purple
B Range Corresponds to ETCO2 0.5-2%: dark tan-light tan
C Range Corresponds to ETCO2 2-5%: light tan-yellow
False-Positive Results: yellow color change without successful endotracheal intubation
Difficult Intubation with Prolonged Bag Ventilation: air previously pushed into the stomach during bag ventilation may cause yellow color change during the first few breaths
However, if Color Remains Yellow After >4-5 breaths, this Indicates Endotracheal Intubation (Anesth Analg, 1989) [MEDLINE]
Epinephrine (see Epinephrine): acidic medication which can cause (non-tidal) yellow color change
Lidocaine (see Lidocaine): acidic medication which can cause (non-tidal) yellow color change
Regurgitation of Gastric Contents During Intubation: gastric acid can cause (non-tidal) yellow color change
False-Negative Results: lack of yellow color change even with successful endotracheal intubation
Acute Pulmonary Embolism (PE) (see Acute Pulmonary Embolism): due to decreased pulmonary blood flow and decreased delivery of carbon dioxide to the lungs
Airway Obstruction: indicator may not turn yellow, due to poor carbon dioxide exchange across the obstructed airway (Emerg Med J, 2003) [MEDLINE]
Cardiac Arrest (see Cardiac Arrest): due to decreased pulmonary blood flow and decreased delivery of carbon dioxide to the lungs
If Chest Compressions are Adequate (with Adequate Blood Flow to the Lungs), Indicator Will Likely Turn Yellow
Indicator Has Only 69% Sensitivity for Endotracheal Intubation When Used During Cardiopulmonary Resuscitation (Ann Emerg Med, 1992) [MEDLINE]
Endotracheal Tube Cuff Leak
When Using Colorimetric Carbon Dioxide Indicator: cuff leak (with endotracheal tube still properly positioned in the trachea) will typically produce a weak yellow color change (due to loss of carbon dioxide around the endotracheal tube)
When Using Waveform Capnography: cuff leak (with endotracheal tube still properly positioned in the trachea) results in decreased amplitude of the plateau (due to loss of carbon dioxide around the endotracheal tube)
Clinical Efficacy
Sensitivity of End-Tidal Carbon Dioxide Detection Approaches 100% in Non-Cardiac Arrest Patients
Sensitivity of End-Tidal Carbon Dioxide Detection is Variable in Cardiac Arrest Patients: ranges from 62-100% in various studies (depending on the modality used and the duration of cardiac arrest)
In Non-Cardiac Arrest, Infrared Capnometry and Infrared Capnography Have a 100% Sensitivity/100% Specificity in Detecting Endotracheal Intubation (Intensive Care Med. 2002) [MEDLINE]
In Cardiac Arrest, Infrared Capnometry Has a 88% Sensitivity/100% Specificity in Detecting Endotracheal Intubation (Intensive Care Med. 2002) [MEDLINE]
Principle/Technique: end-tidal carbon dioxide monitor attached to the end of the endotracheal tube uses infrared absorption to detect carbon dioxide
Displays Either Waveform Capnography or Digital Readout
Clinical Efficacy
Sensitivity of End-Tidal Carbon Dioxide Detection Approaches 100% in Non-Cardiac Arrest Patients
Sensitivity of End-Tidal Carbon Dioxide Detection is Variable in Cardiac Arrest Patients: ranges from 62-100% in various studies (depending on the modality used and the duration of cardiac arrest)
In Non-Cardiac Arrest, Infrared Capnometry and Infrared Capnography Have a 100% Sensitivity/100% Specificity in Detecting Endotracheal Intubation (Intensive Care Med. 2002) [MEDLINE]
In Cardiac Arrest, Infrared Capnometry Has a 88% Sensitivity/100% Specificity in Detecting Endotracheal Intubation (Intensive Care Med. 2002) [MEDLINE]
Esophageal Detector Device
Technique
Uses Suction Applied with Syringes (or Bulb Suction Device) to Distinguish the Trachea from Esophagus
Trachea is Rigid and Allows Free Flow of Air into the Device
Esophagus is Collapsible and Does Not Allow Free Flow of Air When Suction is Applied
Transtracheal Ultrasound
Technique
Advantages
Technique Can Be Performed Quickly and Offers Real-Time Information
Technique is Independent of Pulmonary Blood Flow and Does Not Require Lung Ventilation
Clinical Efficacy
Systematic Review/Meta-Analysis of Transtracheal Ultrasound for Confirmation of Endotracheal Tube Placement (Can J Anaesth, 2015) [MEDLINE]: n = 11 studies
Transtracheal Ultrasound is a Useful Tool to Confirm Endotracheal Tube Placement with Acceptable Sensitivity/Specificity: it can be used as a preliminary test in emergency situations before final confirmation by capnography
Sensitivity: 98%
Specificity: 98%
Systematic Review/Meta-Analysis of Transtracheal Ultrasound for Confirmation of Endotracheal Tube Placement (Resuscitation, 2015) [MEDLINE]
Transtracheal Ultrasound is a Useful Tool to Confirm Endotracheal Tube Placement
Sensitivity: 93%
Specificity: 97%
Combination of Tracheal (to Determine Endotracheal Tube Position) and Pleural Ultrasound (to Detect Lung Sliding) is Superior to Auscultation in Determining Endotracheal Tube Location (Anesthesiology, 2016) [MEDLINE]: small, randomized trial
Recommendation (2022 American Society of Anesthesiologists Practice Guidelines for Management of the Difficult Airway) (Anesthesiology, 2022) [MEDLINE]
Recommendations for Confirmation of Tracheal Intubation
Confirm Endotracheal Intubation Using Capnography or End-Tidal Carbon Dioxide Monitoring
When Uncertain About the Location of the Endotracheal Tube, Determine Whether to Either Remove it and Attempt Ventilation or Use Additional Techniques to Confirm Endotracheal Rube Positioning
Exclusion of Mainstem Bronchial Endotracheal Tube Placement
CXR May Be Used to Confirm Endotracheal Tube Placement
Depth of Endotracheal Tube Insertion
Technique
Depth of Endotracheal Tube Insertion May Be Used to Confirm Endotracheal Tube Placement
Measurement at Teeth/Gums is Preferred, Since These are Fixed Landmarks
Clinical Efficacy
Endotracheal Tube is Usually Inserted to a Depth of 20-21 cm in Females and 22-23 cm in Males (BMJ, 2010) [MEDLINE]
Transtracheal Ultrasound
Clinical Efficacy
Transtracheal Ultrasound May Be Used to Confirm Ventilation Via Detection of Lung Sliding (Acta Anaesthesiol Scand, 2011) [MEDLINE]: lung sliding observed in only one lung indicates mainstem bronchial intubation
Combination of Tracheal (to Determine Endotracheal Tube Position) and Pleural Ultrasound (to Detect Lung Sliding) is Superior to Auscultation in Determining Endotracheal Tube Location (Anesthesiology, 2016) [MEDLINE]: small, randomized trial
Exchange of Endotracheal Tube
Reasons for Exchange of Endotracheal Tube
Endotracheal Tube Cuff Leak
Discrepancy Between Endotracheal Tube Size and Tracheal Diameter (Especially in a Patient with Tracheomalacia)
Pilot Balloon Line or Cuff Leak: some cases of severed pilot balloon lines can be remedied with a pilot balloon line repair kit (assuming the leak is at/near the pilot balloon itself, allowing the pilot balloon line to be cut and repaired)
Mucous Plugging Due to Inadequate Saline Lavage and Suctioning of the Endotracheal Tube
Example: in postoperative patients with tracheal resection, suctioning is frequently discouraged to avoid disruption of the anastomosis -> these patients can rapidly develop concretions within the endotracheal tube within a matter of days, leading to life-threatening endotracheal tube obstruction with inability to ventilate
Gradual Development of Endotracheal Tube Obstruction is Manifested by an Increasing Peak Airway Pressure-Plateau Pressure Difference
Risks of Endotracheal Tube Exchange
Airway Trauma: since intubation itself contributes to at least some degree of laryngeal and tracheal mucosal injury (even in the best of circumstances), reintubations can be expected to increase the risk of this trauma to some extent
Gum Elastic Bougie (Plastic Stylet): a plastic intubating stylet is the most commonly used method to change a dysfunctional endotracheal tube in a patient whose airway is not anticipated to be difficult
While Endotracheal Tube Change Can Be Performed Blindly (without Concomitant Airway Visualization) in Many Cases, Use of a Direct Laryngoscope/Video Laryngoscope is Highly Recommended in Case the Operator is Unable to Pass the New Endotracheal Tube Through the Vocal Cords
Endotracheal Tube Changer: a plastic hollow-bore tube changer (with adapters to allow either supplemental oxygen therapy or bag ventilation) is preferred in a patient whose airway is anticipated to be difficult
While Endotracheal Tube Change Can Be Performed Blindly (without Concomitant Airway Visualization) in Many Cases, Use of a Direct Laryngoscope/Video Laryngoscope is Highly Recommended in Case the Operator is Unable to Pass the New Endotracheal Tube Through the Vocal Cords
Removal of the Endotracheal Tube with Reintubation by Any of the Methods Described Above: this method can be used by experienced operators in a patient whose airway is not anticipated ot be difficult
Endotracheal Tube (ETT) Movement with Head Positioning
ETT Tip Movement Follows Direction of Chin Movement
Neck Flexion (Chin Downward): ETT tip moves downward
Neck Extension (Chin Upward): ETT tip moves upward
Inability to Intubate
General Comments
Supraglottic Airways Can Be Placed into the Pharynx and Utilized to Provide Oxygenation, Ventilation, and Anesthetic Gas Administration without the Need for Endotracheal Intubation
Use for Respiratory Failure in the Prehospital Setting
Use in Operating Room with/without General Anesthesia
Use of General Airway Management
Use for Emergency Airway Management When Endotracheal Intubation is Unsuccessful
Use as a Conduit for Endotracheal Intubation
Use in the Hospital Setting s Part of the Emergency Airway Algorithm
Use for Emergency Airway Management When Endotracheal Intubation is Unsuccessful
Use as a Conduit for Endotracheal Intubation
Types of Supraglottic Airways
Laryngeal Mask Airway (LMA)
Other Supraglottic Devices
Combitube
Laryngeal Tube
Pharyngeal Tube
Laryngeal Mask Airway (LMA)
Rationale
Laryngeal Mask Airway Rests in the Hypopharynx (Facing the Glottis) Forming a Seal Over the Laryngeal Inlet to Allow Mask Ventilation
Laryngeal Mask Airway is Generally Less Stimulating than Endotracheal Intubation
Laryngeal Mask Airway Does Not Fully Protect Against Aspiration
Laryngeal Mask Airway Does Not Prevent Laryngospasm
Indications
Temporary Ventilation During a Surgical Procedure
During Emergency Airway Management When an Endotracheal Tube is Not Initially Desired or Cannot Be Successfully Placed by Laryngoscopy (Can J Anaesth, 2005) [MEDLINE]
Clinical Efficacy
Laryngeal Mask Airway Can Be Placed by Emergency Medical Response Personnel in the Field with Subsequent Exchange for an Endotracheal Tube During Transport or in the Emergency Department (Prehosp Emerg Care, 2007) [MEDLINE]
Laryngeal Mask Airway Placement During Out-of-Hospital Cardiac Arrest was Safer than Bag-Valve-Mask Ventilation (Am J Emerg Med, 2015) [MEDLINE]
Laryngeal Mask Airway Placed During Out-of-Hospital Cardiac Arrest Resulted in Improved 72 hr Survival, as Compared to Endotracheal Intubation (JAMA, 2018) [MEDLINE]
In the AIRWAYS-2 Trial, Laryngeal Mask Airway Placed During Out-of-Hospital Cardiac Arrest Did Not Impact the 30-Day Mortality Rate (JAMA, 2018) [MEDLINE]
Contraindications to Use of Laryngeal Mask Airway
Esophageal Varices (see Esophageal Varices): due to risk of hemorrhage or perforation
Gag Reflex (Due to Risk of Emesis/Aspiration)
Gag Reflex Can Be Removed by Using Pharmacologic Paralysis
Gastroesophageal Reflux Disease (GERD) (see Gastroesophageal Reflux Disease): since LMA’s do not offer the same degree of protection against aspiration as endotracheal intubation, they generally should not be used in patients with significant gastroesophageal reflux (except in emergency situations)
However, LMA with a Gastric Decompression Port May Be Preferred in this Population
Mild GERD is Probably Not a Contraindication to LMA Use
Obesity with BMI >35 kg/m2, Limited Access to Airway During Surgery, Surgery Expected to Last >90 min, and/or Use of Lithotomy Position During Surgery
When Used for Airway Management During Surgery, Obesity Increases the Amount of Time Required for LMA Insertion (Cochrane Database Syst Rev, 2013) [MEDLINE]: probably not clinically important (although the failure rate of LMA’s is approximately 3-5%)
When Used for Airway Management During Surgery, Obesity Increases the Risk of Gastric Insufflation
When Used for Airway Management During Surgery, Obesity Increases the Peak Inspiratory Pressure (PIP)
When Used for Airway Management During Surgery, Obesity Increases the Risk of Mask Leak, Although it Does Not Appear to Affer Ventilation (Cochrane Database Syst Rev, 2013) [MEDLINE]
When Used for Airway Management During Surgery in Obese Patients, LMA Significantly Improves Oxygenation During and After Surgery: suggests improved pulmonary performance
Oropharyngeal Trauma with Risk of Perforation
Proximal Esophageal Trauma with Risk of Perforation
Upper Airway Foreign Body (see Airway Foreign Body): since foreign body can be inadvertently moved into the trachea, resulting in tracheal obstruction
Determinants of Proper Laryngeal Mask Airway Sizing
Patient Anatomy
Laryngeal Mask Airway Size: the usual adult LMA sizes are 3/4/5/6 (most LMA’s are available in full sizes, some are available in half sizes too)
Cuff Inflation
General Sizing
Adult Female (Up to 100 kg): usually size 4
Adult Male (Up to 100 kg): usually size 5
Cuff Volume: appropriate cuff volume is usually provided by the manufacturer (note: cuff overinflation should be avoided to prevent worsening mask seal and/or injury the oropharyngeal mucosa)
Size 4 LMA: approximate cuff volume 30 mL (if larger cuff volume is required to maintain an adequate seal, a larger LMA should be placed or the patient should be endotracheally intubated)
Size 5 LMA: approximate cuff volume 40 mL (if larger cuff volume is required to maintain an adequate seal, a larger LMA should be placed or the patient should be endotracheally intubated)
Laryngeal Mask Airway Insertion
Anesthesia
Adequate Anesthesia (General Anesthesia, Intravenous Sedation) is Required Prior to LMA Inseriton to Avoid Gagging, Coughing, Laryngospasm, Breath Holding, and Straining
However, Some Patients Can Tolerate Placement with Topical Anesthesia Alone
Pharmacologic Neuromuscular Blockade Can Be Utilized to Facilitate LMA Placement: decreases the incidence of gagging, laryngospasm, and coughing
Use of Bronchoscopy for Laryngeal Mask Airway Placement
Bronchoscope Can Be Utilized to Verify Correct Placement of the LMA
Features Which Indicate Correct Laryngeal Mask Airway Placement
Ability to Ventilate without Difficulty: as determined by tidal volume, peak airway pressure <20 cm H20, and chest rise
Normal Capnography
No Leak (with Peak Airway Pressure <20 cm H2O)
Other Aspects
With Correct LMA Positioning, Cuff Inflation May Result in Outward Movement of the LMA and Slight Swelling in the Neck
Technique for LMA Fastrach Insertion
Deflate the LMA Cuff Completely and Lubricate Both Sides with Water-Soluble Lubricant
Standing at the Head of the Bed, with LMA in Dominant Hand, Place Mask on the Palate and Advance Along Palate Until Resistance is Felt
In Proper Position, the Handle Will Have a Slight Upward Angle (and Will Not Be Horizontal)
Inflate LMA Fastrach Cuff to Maintain Seal (Pressure <40 cm H2O)
Check for Proper Ventilation with Bag-Valve and Capnography
Technique for Air-Q Insertion
Similar to Placement of the LMA Classic, Except that the Air-Q Does Not Need to Ride Against the Palate During Insertion: cuff is stiff, so that it does not need to touch the pharyngeal structures during insertion
Inflate Air-Q Cuff to Maintain Seal (Pressure <40 cm H2O)
Difficulties Associated with Laryngeal Mask Airway Placement and Function
Epiglottis Entrapment (Tip of Epiglottis Flipped Over by the Laryngeal Mask)
Management
“Up-Down” Technique: withdraw LMA 2-4 cm without deflating the cuff and then reinsert
Patient Maintaining Upper Airway Tone (Which Prevents Proper Seating of the Mask in the Larynx)
Management
Increase Anesthesia/Sedation
Inadequate Laryngeal Mask Seal
Etiology
Folded Over LMA Cuff
Improper LMA Size
Since Larger Size LMA’s Generally Provide a Better Seal with Lower Cuff Inflation Volumes and Pressures, as Compared to Smaller Size LMA’s, Replacing with a Larger LMA May Remedy the Problem
Inadequate Air in the LMA Cuff
High Peak Airway Pressure
Management
Add Air to Cuff (If Necessary)
Replace with Same or Larger LMA
Transition to Endotracheal Intubation: if unable to maintain adequate seal
Poor Patient Anatomy Contributing to Difficult LMA Placement
Management
Rotational Placement of LMA (with Partially-Inflated Cuff) May Facilitate Placement in Difficult Cases
Placement with the Aid of Ultrasound or Bronchoscopy
Intubating Via the Laryngeal Mask Airway
General Comments
While Intubation Through an Intubating Laryngeal Mask Airway Can Be Achieved Blindly, May Providers Utilize a Bronchoscope to Intubate by this Technique
Endotracheal Tube is Loaded Onto the Bronchoscope and the Bronchoscope/Tube are Passed Through the LMA Channel
Technique for Intubation Via Laryngeal Mask Airway Fastrach
General Comments
LMA Fastrach Contains a Bar Which Elevates the Epiglottis as the Endotracheal Tube Passes Through the Aperture
LMA Fastrach Has a Ramp in the Intubating Channel Which Directs the Endotracheal Tube Anteriorly and Centrally to Facilitate Movement into the Trachea (and Minimize Damage to Glottis)
LMA Fastrach May Use Either a Standard Endotracheal Tube or a Proprietary Non-Kinking Endotracheal Tube
If Standard Endotracheal Tube is Used, Warm it Beforehand (to Increase Flexibility) and Insert it onto a Bronchoscope, then Insert the Bronchoscope/Endotracheal Tube Asssembly into the LMA with the Curvature Reversed (To Facilitate the Tip Exiting the LMA at a Shallow Angle and Entering the Trachea)
At 15 cm Depth, an Endotracheal Tube Emerges from the LMA and Lifts the Epiglottis Elevating Bar
Proprietary Endotracheal Tube
Vertical Black Line Should Face the Operator (This Aligns the Bevel with the Vocal Cords)
Horizontal Black Line Marks the 15 cm Insertion Depth (at Which the Tube Exits the LMA)
Perform a “Skillet Lift” Using the LMA Fastrach Handle to Align the Cuff with the Glottic Opening
Gently Advance the Endotracheal Tube: if resistance is encountered, glottic alignment is not correct
When Endotracheal Placement is Confirmed, Deflate the LMA Fastrach Cuff to Relieve the Mucosal Pressure
After Intubation, Carefully Remove the LMA Fastrach
LMA Fastrach May Remain in Place for Several Hours Prior to Removal
Technique for Intubation Via the Air-Q
General Comments
Large Adult Size Air-Q Can Accomodate a 8.5 Endotracheal Tube
Air-Q Has a Mild Curvature and is Designed to Utilize a Standard Endotracheal Tube: it does not require a specialized non-kinking endotracheal tube
Lubricate the Endotracheal Tube with Water-Soluble Lubricant
Remove the 15 mm Bag Connector and Insert the Endotracheal Tube into the Lumen
Move Endotracheal Tube Up and Down in the Lumen to Lubricate the Channel
Advance the Endotracheal Tube into the Trachea
May Need to Gently Insert/Withdraw the Air-Q to Facilitate Endotracheal Tube Passage
Inflate the Endotracheal Tube Cuff
When Endotracheal Placement is Confirmed, Deflate the Air-Q Cuff to Relieve the Mucosal Pressure
After Confirmation of Endotracheal Tube Placement, Remove the Air-Q Using the Removal Stylet: this decreases the risk of damage to the pilot balloon
Air-Q May Remain in Place for Several Hours Prior to Removal
Ventilation Technique
Spontaneous Ventilation
Advantages
Better Tolerance of LMA Malpositioning
Decreases Air Leak Around the LMA
Limits the Development of Gastric Insufflation
Positive-Pressure Ventilation
Pressure-Limited Ventilation (Pressure Support, Pressure Control) is Used More Commonly than Volume-Limited Ventilation, Since the LMA Does Not Seal the Pharynx and There is Leak Around the Device (with Resulting Gastric Insufflation and/or Inadequate Ventilation)
LMA’s are Generally Designed for Use with Peak Airway Pressure <20 cm H2O: higher peak airway pressure may result in LMA leak and/or gastric insufflation
LMA ProSeal was Designed for Use with Somewhat Higher Peak Airway Pressures (<25 cm H2O): cuff has a posterior extension which provides a “double seal”
Advantages
Allows Control of Respiratory Rate and Tidal Volume
Ventilation is Assured During Deeper Levels of Sedation
Adverse Effects/Complications
General Comments
Laryngeal Mask Airway-Associated Complications are Low: occur in approximately 0.15% of cases (Anesth Analg, 1996) [MEDLINE]
High Laryngeal Mask Airway Cuff Pressure May Increase the Risk of Airway Complications (Anesthesiology, 2010) [MEDLINE] (Can J Anaesth, 2013) [MEDLINE]
Laryngeal Mask Airway May Function to Some Extent to Seal Off the Trachea from Aspiration of Regurgitated Gastric Contents
However, Vomiting or Increase in Intragastric Pressure Can Overcome this Protection, Resulting in Aspiration (Br J Anaesth, 2002) [MEDLINE]
Laryngeal Mask Airway Decreases Lower Esophageal Sphincter Tone Via a Reflex Mechanism (Br J Anaesth, 1992) [MEDLINE]: this is similar to the reflex which occurs while swallowing a bolus of food
This Results in Increased Acid Reflux into the Esophagus During Lithotomy and Trendelenburg Positioning (Can J Anaesth, 1999) [MEDLINE]
Prevention
Patient Selection
Assess Risk Factors for Aspiration
Assess Lung/Chest Wall Compliance for Factors that Might Increase Peak Airway Pressure
Procedure Selection (Accounting for Expected Patient Positioning Which Might Contribute to Aspiration)
Maintenance of Adequate Depth of Anesthesia During Laryngeal Mask Airway Insertion and During Surgery
Minimization of Peak Airway Pressure During Mechanical Ventilation to Avoid Gastric Insufflation
Ensure Adequate Reversal of Neuromuscular Blockade Prior to Emergence from General Anesthesia
Use of Laryngeal Mask Airway with Gastric Decompression Port (Anaesthesia, 2011) [MEDLINE]
Incision of the Cricothyroid Membrane with Insertion of a Tube to Establish an Artificial Airway
History
Cricothyroidotomy (Initially Referred to as “High Tracheostomy”) was First Performed by Dr. Chevalier Jackson in 1909: cases were often performed due to upper airway obstruction related to diphtheria
Due to Complications of Tracheal Stenosis, He Later Criticize the Use of Cricothyroidotomy
Epidemiology
The Historical Rate of Cricothyroidotomies Has Been Demonstrated to Decrease Over Time, Attributable to Several Factors (Acad Emerg Med, 1998) [MEDLINE]
Adoption of Rapid Sequence Intubation (RSI)
Decreased Concern Related to the Perfomance of Endotracheal Intubation in Trauma Patients Without Initial Evaluation to Rule Out Cervical Spinal Cord Injury
Establishment of Emergency Medicine Residencies with the Presence of 24 hr Supervising Emergency Medicine Faculty
Rates of Cricothyroidotomy Might Be Expected to Continue to Decline with the Increased Use of Video Laryngoscopy and the Advancement of Other Airway Management Techniques
In a Single-Center Retrospective Study, Cricothyroidotomy Comprised 1% of All Emergency Department Intubations (and 10.9% of All Prehospital Intubations) (J Emerg Med. 2003) [MEDLINE]
Indications
General Indications for Cricothyroidotomy
Inability to Intubate Patient
Contraindication to Intubation
Upper Airway Obstruction: note that cricothyroidotomy will only be effective if the airway obstruction is proximal to the site of the cricothyroidotomy
Specific Etiologies Requiring Cricothyroidotomy (Acad Emerg Med, 1998) [MEDLINE]
Facial Fracture: 32% of cases
Emesis in the Airway: 32% of cases
Failure of Intubation (in the Absence of Clinical Issues): 11% of cases
Traumatic Upper Airway Obstruction: 7% of cases
Relative Contraindications
Childhood (<5-12 y/o): since the childhood airway is funnel-shaped with the narrowest aspect at the cricoid ring rather than at the vocal cords (with an increased risk of developing subglottic stenosis) and procedure can damage the relatively soft cricoid cartilage in children
Remote Radiation Therapy (or Other Deformity/Scarring) Which May Alter the Upper Airway Anatomy
Tumor
Intrinsic Airway Tumor
Technique
Cricothyroid Membrane Lies Below the Thyroid Cartilage and Above the Cricoid Cartilage
Laterally on Both Sides of the Cricothyroid Membrane are the Cricothyroideus Muscles
Location of the Cricothyroid Membrane by Palpation Can Be Difficult Even for Experienced Providers with Surgical Airway Experience (Success Rates ≤50%) (Can J Anaesth, 2016) [MEDLINE]: this is especially true in obese patients (Anaesthesia, 2015) [MEDLINE]
Location of the Cricothyroid Membrane by Ultrasound: may be useful, but studies are lacking
Cook Melker Kit Procedure
Components: 6 mL syringe, 18 gauge needle with overlying catheter, a guide wire, a tissue dilator, cuffed cricothyroidotomy tube, and tracheostomy tape
Time Required: 1-4 min (Anaesthesist, 2003) [MEDLINE]
Steps
Stand at the Patient’s Right Side
Immobilize the Larynx by Holding the Thyroid Cartilage with the Left Hand
With Right Hand, Insert Needle (Pointed at a Downward 45 Degree Angle) into the Cricothyroid Membrane with Syringe Filled with Saline, Aspirating as You Go: watch for air bubbles into the syringe, indicating that you are in the trachea
Remove Syringe and Pass Wire Through the Needle
Remove Needle
Make a 1-2 cm Horizontal Incision Through the Skin and Cricothyroid Membrane: take care to not incise too deep (which may injury the posterior tracheal wall) or with the blade oriented superiorly (which may injure the vocal cords)
Thread the Dilator/Tube Assembly Over the Wire into the Airway
Remove the Dilator and Wire
Secure Airway Tube with Tracheostomy Tape and Attach to Either Bag Ventilation or Mechanical Ventilator
Complications
Early Adverse Effects/Complications
Bleeding: usually occurs and can be controlled with direct pressure/packing
Cricoid Cartilage Fracture
Infection
Passage of Tube into Extratracheal Location
Posterior Tracheal Wall Perforation
Thyroid Cartilage Fracture
Tracheal Ring Fracture
Unintentional Tracheostomy
Late Adverse Effects/Complications
Subglottic Stenosis
Voice Changes
Adverse Effects and Complications of Airway Management, Endotracheal Intubation, and Invasive Mechanical Ventilation
Patient Awareness of Paralysis During Endotracheal Intubation
Study of Awareness of Paralysis in Emergency Department Patients Undergoing Endotracheal Intubation (Chest, 2023) [MEDLINE]: n = 886
Approximately 7.4% of Patients Recalled Awareness of Paralysis During Endotracheal Intubation (95% CI: 5.8-9.4)
Logistic Regression Model Demonstrated that Decreased Level of Consciousness Prior to Intubation was Associated with Lower Odds of Awareness (Adjusted Odds Ratio 0.39; 95% CI: 0.22-0.69)
The Class of Neuromuscular Blocking Agent Used, Sedative Used, Preintubation Shock Index, and Postintubation Sedation were Not Significantly Associated with Recall of Paralysis During Endotracheal Intubation
Impact on Medical Malpractice Claims
Significant Morbidity/Mortality (as Well as Medical Malpractice) is Related to Adverse Events/Complications of Airway Management and Endotracheal Intubation
Inadequate Ventilation, Esophageal Intubation, and Difficult Endotracheal Intubation are the Most Common Mechanisms of Respiratory Adverse Events/Complications Associated with Endotracheal Intubation/Mechanical Ventilation by Anesthesiologists (Anesthesiology, 1991) [MEDLINE]
US Review of Airway Complications in Patients Undergoing General Anesthesia (Anesthesiology, 2009) [MEDLINE]: mortality rate of 1.1 per million
British National Health Service Review of Major Airway Complications in Patients Undergoing General Anesthesia (Br J Anaesth. 2011) [MEDLINE]: 46 events per million (associated mortality of 5.6 per million)
British National Health Service Review of Major Airway Complications Noted that 25% of Reported Airway Events Occurred in the Intensive Care Unit or Emergency Department (and 61% of Those Events Resulted in Permanent Patient Harm or Death) (Br J Anaesth, 2011) [MEDLINE]
Closed Claims Analysis of Difficult Endotracheal Intubation by Anesthesiologists (Comparison of 2000-2012 to 1993-1999 Time Periods) (Anesthesiology, 2019) [MEDLINE]
Patients in 2000-2012 Difficult Intubation Claims were Sicker (78% American Society of Anesthesiologists, ASA, Physical Status III-V) and Had More Emergency Procedures (37%) as Compared to Patients in 1993-1999 Claims (47% ASA Physical Status III-V; P < 0.001 and 22% Emergency; P = 0.025)
More Difficult Endotracheal Intubation Events Occurred in Nonperioperative Locations in 2000-2012 than 1993-1999 (23% vs 10%; P = 0.035)
Outcomes Differed Between Time Periods (P < 0.001), with a Higher Proportion of Death in 2000-2012 claims (73% vs 42% in 1993-1999 Claims; P < 0.001 Adjusted for Multiple Testing)
In 2000-2012 Claims, Preoperative Predictors of Difficult Endotracheal Intubation were Present in 76% of Cases
In the 97 Claims with Sufficient Information for Assessment, Inappropriate Airway Management Occurred in 73% of Cases (κ = 0.44-0.66)
A “Can’t Intubate, Can’t Oxygenate” Emergency Occurred in 80 Claims with Delayed Surgical Airway in 39% of Cases
Multiple Intubation Attempts
Multiple Intubation Attempts is a Risk Factor for Adverse Events/Complications of Airway Management and Endotracheal Intubation
In Emergency Endotracheal Intubations Performed in Critically Ill Patients Suffering Deterioration, As Compared to ≤2 Attempts, Repeated Attempts (≥3) were Significantly Associated with Increased Incidence of Hypoxemia (11.8% vs 70%), Regurgitation of Gastric Contents (1.9% vs 22%), Aspiration of Gastric Contents (0.8% vs 13%), Bradycardia (1.6% vs 21%), and Cardiac Arrest (0.7% vs 11%; P<0.001) (Anesth Analg, 2004) [MEDLINE]
In Emergency Department Intubations, ≥3 Intubation Attempts were Associated with a Significantly Increased Rate of Adverse Events (35% vs 9%) (Ann Emerg Med, 2012) [MEDLINE]
Patients Requiring 1 Intubation Attempts Had a 14.2% Adverse Event Rate, Patients Requiring 2 Intubation Attempts Had a 47.2% Adverse Event Rate, and Patients Requiring 3 Intubation Attempts in the Emergency Department Had a 63.6% Adverse Event Rate (Acad Emerg Med, 2013) [MEDLINE]
Intubation Bundles
Intubation Bundles Can Decrease the Incidence of Post-Intubation Adverse Effects/Complications in the Intensive Care Unit (Intensive Care Med, 2010) [MEDLINE]: n = 244
Bundle Components
Capnography
Cricoid Pressure
Intravenous Fluid Loading
Preoxygenation with Noninvasive Positive-Pressure Ventilation
Preparation and Early Administration of Sedation
Presence of Two Operators
Protective Ventilation
Rapid Sequence Induction
Vasopressor Use (If Required)
Specific Adverse Effects and Complications of Endotracheal Intubation and Invasive Mechanical Ventilation
Safe intrahospital transport of critically ill ventilator-dependent patients. Chest 1989; 96:631-635 [MEDLINE]
Airway considerations in the management of patients requiring long-term endotracheal intubation. Anesth Analg. 1992;74(2):276 [MEDLINE]
Unplanned extubations in the adult intensive care unit. Am J Respir Crit Care Med 1998; 157:1131-1137 [MEDLINE]
Death and other complications of emergency airway management in critically ill adults. Anesthesiology 1995; 82:367-376 [MEDLINE]
Bedside procedures: solutions to the pitfalls of intrahospital transport. Crit Care Clin 2000; 16:1-6 [MEDLINE]
Difficult airway management in the emergency department. J Emerg Med. 2002 Jan;22(1):31-48 [MEDLINE]
Clinical practice guidelines for sustained neuromuscular blockade in the adult critically ill patient. Crit Care Med. 2002 Jan;30(1):142-56 [MEDLINE]
Towards evidence based emergency medicine: best BETs from the Manchester Royal Infirmary. Colourimetric CO(2) detector compared with capnography for confirming ET tube placement. Emerg Med J 2003: 20: 265-266 [MEDLINE]
The effectiveness of out-of-hospital use of continuous end-tidal carbon dioxide monitoring on the rate of unrecognized misplaced intubation within a regional emergency medical services system. Ann Emerg Med 2005; 45:497-503 [MEDLINE]
Clinical review: management of difficult airways. Crit Care 2006;10:243. doi: 10.1186/cc5112 [MEDLINE]
2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Part 8: adult advanced cardiovascular life support. Circulation 2010; 122(18 Suppl 3):S729-S767 [MEDLINE]
Airway management in critically ill patients. Lung 2011; 189:181-192 [MEDLINE]
Emergency airway management: the difficult airway. Emerg Med Clin North Am 2012; 30:401-420 [MEDLINE]
Practice guidelines for management of the difficult airway: an updated report by the American Society of Anesthesiologists Task Force on Management of the Difficult Airway. Anesthesiology. 2013;118:251–270 [MEDLINE]
The effect of body mass index on intubation success rates and complications during emergency airway management. Intern Emerg Med. 2013 Feb;8(1):75-82. Epub 2012 Nov 25 [MEDLINE]
Heated humidified high-flow nasal oxygen in adults: mechanisms of action and clinical implications. Chest. 2015;148(1):253–261 [MEDLINE]
Endotracheal intubation in the ICU. Crit Care. 2015;19:258 [MEDLINE]
Experts’ guidelines of intubation and extubation of the ICU patient of French Society of Anaesthesia and Intensive Care Medicine (SFAR) and French-speaking Intensive Care Society (SRLF) : In collaboration with the pediatric Association of French-speaking Anaesthetists and Intensivists (ADARPEF), French-speaking Group of Intensive Care and Paediatric emergencies (GFRUP) and Intensive Care physiotherapy society (SKR). Ann Intensive Care. 2019 Jan 22;9(1):13. doi: 10.1186/s13613-019-0483-1 [MEDLINE]
Airway Management in Critical Illness: An Update. Chest. 2020 Apr;157(4):877-887. doi: 10.1016/j.chest.2019.10.026 [MEDLINE]
Simulation Training for Critical Care Airway Management: Assessing Translation to Clinical Practice Using a Small Video-Recording Device. Chest 2020 Jul;158(1):272-278. doi: 10.1016/j.chest.2020.01.047 [MEDLINE]
2022 American Society of Anesthesiologists Practice Guidelines for Management of the Difficult Airway. Anesthesiology. 2022 Jan 1;136(1):31-81. doi: 10.1097/ALN.0000000000004002 [MEDLINE]
Indications
Part 7: Adult Advanced Cardiovascular Life Support: 2015 American Heart Association Guidelines Update for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation. 2015 Nov 3;132(18 Suppl 2):S444-64. doi: 10.1161/CIR.0000000000000261 [MEDLINE]
Effect of Bag-Mask Ventilation vs Endotracheal Intubation During Cardiopulmonary Resuscitation on Neurological Outcome After Out-of-Hospital Cardiorespiratory Arrest: A Randomized Clinical Trial. JAMA 2018; 319:779 [MEDLINE]
Effect of a Strategy of a Supraglottic Airway Device vs Tracheal Intubation During Out-of-Hospital Cardiac Arrest on Functional Outcome: The AIRWAYS-2 Randomized Clinical Trial. JAMA 2018; 320:779 [MEDLINE]
Effect of a Strategy of Initial Laryngeal Tube Insertion vs Endotracheal Intubation on 72-Hour Survival in Adults With Out-of-Hospital Cardiac Arrest: A Randomized Clinical Trial. JAMA 2018; 320:769 [MEDLINE]
Assessment for Upper Airway Obstruction
A life-saving maneuver to prevent food-choking. JAMA. 1975;234(4):398 [MEDLINE]
Heimlich versus a slap on the back. N Engl J Med. 1979;300(17):990 [MEDLINE]
The choking controversy: critique of evidence on the Heimlich maneuver. Crit Care Med. 1979;7(10):475 [MEDLINE]
Chest compression–an alternative to the Heimlich manoeuver? Resuscitation. 1992;24(1):91 [MEDLINE]
Traumatic rupture of the stomach secondary to Heimlich maneuver. Am J Emerg Med. 1993;11(6):611 [MEDLINE]
Assessment of upper airway anatomy in awake, sedated and anaesthetised patients using magnetic resonance imaging. Anaesth Intensive Care. 1994;22(2):165 [MEDLINE]
Magnetic resonance imaging of the upper airway. Effects of propofol anesthesia and nasal continuous positive airway pressure in humans. Anesthesiology. 1996;84(2):273 [MEDLINE]
Gastric rupture secondary to successful Heimlich manoeuvre. Postgrad Med J. 1998;74(876):609 [MEDLINE]
Airway pressure with chest compressions versus Heimlich manoeuvre in recently dead adults with complete airway obstruction. Resuscitation. 2000;44(2):105 [MEDLINE]
Rupture of the lesser gastric curvature after a Heimlich maneuver. Surg Endosc. 2003;17(9):1495 [MEDLINE]
Part 4: CPR overview: 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation. 2010;122(18 Suppl 3):S676 [MEDLINE]
Part 5: Adult Basic Life Support and Cardiopulmonary Resuscitation Quality: 2015 American Heart Association Guidelines Update for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation. 2015;132(18 Suppl 2):S414 [MEDLINE]
Airway Maneuvers
Resuscitation–opening the airway. A comparative study of techniques for opening an airway obstructed by the tongue. JACEP. 1976;5(8):588 [MEDLINE]
The effect of airway maneuvers on the unstable C1-C2 segment. A cadaver study. Spine (Phila Pa 1976). 1997;22(11):1215 [MEDLINE]
Cervical spine motion during airway management: a cinefluoroscopic study of the posteriorly destabilized third cervical vertebrae in human cadavers. Anesth Analg. 2000;91(5):1274 [MEDLINE]
Effectiveness of the jaw-thrust maneuver in opening the airway: a flexible fiberoptic endoscopic study. ORL J Otorhinolaryngol Relat Spec. 2005;67(1):39 [MEDLINE]
Airway Adjuncts
The nasopharyngeal airway. Assessment of position by fibreoptic laryngoscopy. Anaesthesia. 1993;48(7):575 [MEDLINE]
The nasopharyngeal airway: dispelling myths and establishing the facts. Emerg Med J. 2005;22(6):394 [MEDLINE]
Preintubation Assessment
Limitations of difficult airway prediction in patients intubated in the emergency department. Ann Emerg Med. 2004 Oct;44(4):307-13 [MEDLINE]
Can an Airway Assessment Score Predict Difficulty at Intubation in the Emergency Department? Emerg Med J 2005 Feb;22(2):99-102. doi: 10.1136/emj.2003.008771 [MEDLINE]
The extended Mallampati score and a diagnosis of diabetes mellitus are predictors of difficult laryngoscopy in the morbidly obese. Anesth Analg. 2008 Dec;107(6):1919-23. doi: 10.1213/ane.0b013e31818a9946 [MEDLINE]
Determination of Difficult Intubation in the ED Am J Emerg Med 2009 Oct;27(8):905-10. doi: 10.1016/j.ajem.2008.07.003 [MEDLINE]
Feasibility of the preoperative Mallampati airway assessment in emergency department patients. J Emerg Med. 2010 Jun;38(5):677-80. doi: 10.1016/j.jemermed.2008.12.019 [MEDLINE]
High STOP-Bang score indicates a high probability of obstructive sleep apnoea. British Journal of Anaesthesia 108 (5): 768–75 (2012) [MEDLINE]
Early identification of patients at risk for difficult intubation in the intensive care unit: development and validation of the MACOCHA score in a multicenter cohort study. Am J Respir Crit Care Med. 2013 Apr 15;187(8):832-9. doi: 10.1164/rccm.201210-1851OC [MEDLINE]
The MACOCHA score is feasible to predict intubation failure of nonanesthesiologist intensive care unit trainees. J Crit Care. 2015 Oct;30(5):876-80. doi: 10.1016/j.jcrc.2015.04.118 [MEDLINE]
Prospective validation of the modified LEMON criteria to predict difficult intubation in the ED. Am J Emerg Med. 2015 Oct;33(10):1492-6. doi: 10.1016/j.ajem.2015.06.038 [MEDLINE]
The diagnostic validity of clinical airway assessments for predicting difficult laryngoscopy using a grey zone approach. J Int Med Res. 2016 Aug;44(4):893-904. doi: 10.1177/0300060516642647 [MEDLINE]
Correlation Between Modified LEMON Score and Intubation Difficulty in Adult Trauma Patients Undergoing Emergency Surgery. World J Emerg Surg 2018 Jul 24;13:33. doi: 10.1186/s13017-018-0195-0. eCollection 2018 [MEDLINE]
Will This Patient Be Difficult to Intubate?: The Rational Clinical Examination Systematic Review. JAMA. 2019 Feb 5;321(5):493-503. doi: 10.1001/jama.2018.21413 [MEDLINE]
Bag-Valve-Mask Ventilation
Simultaneous aortic, jugular bulb, and right atrial pressures during cardiopulmonary resuscitation in humans. Insights into mechanisms. Circulation. 1989;80(2):361 [MEDLINE]
Comparison of self-inflating bags with anesthesia bags for bag-mask ventilation in the pediatric emergency department. Pediatr Emerg Care. 1997;13(5):312 [MEDLINE]
Prediction of difficult mask ventilation. Anesthesiology 2000;92:1229–1236 [MEDLINE]
Hyperventilation-induced hypotension during cardiopulmonary resuscitation. Circulation. 2004;109(16):1960 [MEDLINE]
Death by hyperventilation: a common and life-threatening problem during cardiopulmonary resuscitation. Crit Care Med. 2004;32(9 Suppl):S345 [MEDLINE]
Incidence and predictors of difficult or impossible mask ventilation. Anesthesiology 2006;105:885–891 [MEDLINE]
The effect of leaving dentures in place on bag-mask ventilation at induction of general anesthesia. Anesth Analg. 2007;105(2):370 [MEDLINE]
A two-handed jaw-thrust technique is superior to the one-handed “EC-clamp” technique for mask ventilation in the apneic unconscious person. Anesthesiology. 2010;113(4):873 [MEDLINE]
Face mask ventilation in edentulous patients: a comparison of mandibular groove and lower lip placement. Anesthesiology. 2010;112(5):1190 [MEDLINE]
Efficacy of facemask ventilation techniques in novice providers. Clin Anesth. 2013 May;25(3):193-7 [MEDLINE]
Optimizing Mask Ventilation: Literature Review and Development of a Conceptual Framework. Respir Care. 2015 Dec;60(12):1834-40. doi: 10.4187/respcare.04183 [MEDLINE]
Preparation for Intubation
Body Position
Analysis of the forces and position required for direct laryngoscopic exposure of the anterior vocal folds. Ann Otol Rhinol Laryngol. 1999;108(8):715 [MEDLINE]
Head and neck elevation beyond the sniffing position improves laryngeal view in cases of difficult direct laryngoscopy. J Clin Anesth. 2002;14(5):335 [MEDLINE]
Head-elevated laryngoscopy position: improving laryngeal exposure during laryngoscopy by increasing head elevation. Ann Emerg Med. 2003;41(3):322 [MEDLINE]
Laryngoscopy and morbid obesity: a comparison of the “sniff” and “ramped” positions. Obes Surg. 2004;14(9):1171 [MEDLINE]
Head-Elevated Patient Positioning Decreases Complications of Emergent Tracheal Intubation in the Ward and Intensive Care Unit. Anesth Analg. 2016 Apr;122(4):1101-7 [MEDLINE]
A Multicenter, Randomized Trial of Ramped Position vs Sniffing Position During Endotracheal Intubation of Critically Ill Adults. Chest. 2017 Oct;152(4):712-722. doi: 10.1016/j.chest.2017.03.061 [MEDLINE]
A randomised clinical trial comparing the ‘sniffing’ and neutral position using channelled (KingVision® ) and non-channelled (C-MAC® ) videolaryngoscopes. Anaesthesia. 2018 Jul;73(7):847-855. doi: 10.1111/anae.14289 [MEDLINE]
Effect of inclined positioning on first-pass success during endotracheal intubation: a systematic review and meta-analysis. Emerg Med J. 2022 Apr 7;emermed-2021-211968. doi: 10.1136/emermed-2021-211968 [MEDLINE]
Team-Oriented Approach/Protocol/Check List
An intervention to decrease complications related to endotracheal intubation in the intensive care unit: a prospective, multiple-center study. Intensive Care Med. 2010 Feb;36(2):248-55. doi: 10.1007/s00134-009-1717-8 [MEDLINE]
A program to improve the quality of emergency endotracheal intubation. J Intensive Care Med. 2011 Jan-Feb;26(1):50-6. doi: 10.1177/0885066610384070 [MEDLINE]
The use of cognitive aids during emergencies in anesthesia: a review of the literature. Anesth Analg. 2013 Nov;117(5):1162-71. doi: 10.1213/ANE.0b013e31829c397b [MEDLINE]
Difficult airway response team: a novel quality improvement program for managing hospital-wide airway emergencies. Anesth Analg. 2015 Jul;121(1):127-39. doi: 10.1213/ANE.0000000000000691 [MEDLINE]
The Vortex: a universal ‘high-acuity implementation tool’ for emergency airway management. Br J Anaesth. 2016 Sep;117 Suppl 1:i20-i27. doi: 10.1093/bja/aew175 [MEDLINE]
A Multicenter Randomized Trial of a Checklist for Endotracheal Intubation of Critically Ill Adults. Chest. 2018 Apr;153(4):816-824. doi: 10.1016/j.chest.2017.08.1163 [MEDLINE]
A Decade of Difficult Airway Response Team: Lessons Learned from a Hospital-Wide Difficult Airway Response Team Program. Crit Care Clin. 2018 Apr;34(2):239-251. doi: 10.1016/j.ccc.2017.12.008 [MEDLINE]
Intubation Techniques
Rapid Sequence Intubation (RSI)
General
A comparison of blind nasotracheal and succinylcholine-assisted intubation in the poisoned patient. Ann Emerg Med. 1987;16(6):650 [MEDLINE]
Decreased circulation time in the upper limb reduces the lag time of the finger pulse oximeter response. Can J Anaesth. 1992 Jan;39(1):87-9 [MEDLINE]
Rapid-sequence intubation in head trauma. Ann Emerg Med. 1993;22(6):1008 [MEDLINE]
Critical hemoglobin desaturation will occur before return to an unparalyzed state following 1 mg/kg intravenous succinylcholine. Anesthesiology. 1997;87(4):979 [MEDLINE]
Airway management in the emergency department: a one-year study of 610 tracheal intubations. Ann Emerg Med. 1998;31(3):325 [MEDLINE]
Complications of emergency intubation with and without paralysis. Am J Emerg Med. 1999;17(2):141 [MEDLINE]
The failed intubation attempt in the emergency department: analysis of prevalence, rescue techniques, and personnel. J Emerg Med. 2002;23(2):131 [MEDLINE]
A preliminary study of the optimal anesthesia positioning for the morbidly obese patient. Obes Surg. 2003;13(1):4 [MEDLINE]
Airway management by US and Canadian emergency medicine residents: a multicenter analysis of more than 6,000 endotracheal intubation attempts. Ann Emerg Med. 2005;46(4):328 [MEDLINE]
A prospective, randomised controlled trial comparing the efficacy of pre-oxygenation in the 20 degrees head-up vs supine position. Anaesthesia. 2005;60(11):1064 [MEDLINE]
Nasopharyngeal oxygen insufflation following pre-oxygenation using the four deep breath technique. Anaesthesia. 2006;61(5):427 [MEDLINE]
Rapid sequence induction and intubation: current controversy. Anesth Analg. 2010 May;110(5):1318-25 [MEDLINE]
Neuromuscular blocking agent administration for emergent tracheal intubation is associated with decreased prevalence of procedure-related complications. Crit Care Med. 2012 Jun;40(6):1808-1 [MEDLINE]
Association between repeated intubation attempts and adverse events in emergency departments: an analysis of a multicenter prospective observational study. Ann Emerg Med. 2012 Dec;60(6):749-754.e2 [MEDLINE]
The importance of first pass success when performing orotracheal intubation in the emergency department. Acad Emerg Med. 2013;20(1):71 [MEDLINE]
Neuromuscular blockade improves first-attempt success for intubation in the intensive care unit. A propensity matched analysis. Ann Am Thorac Soc. 2015;12(5):734 [MEDLINE]
Techniques, success, and adverse events of emergency department adult intubations. Ann Emerg Med. 2015 Apr;65(4):363-370.e1 [MEDLINE]
Difficult Airway Society 2015 guidelines for management of unanticipated difficult intubation in adults. Br J Anaesth. 2015 Dec;115(6):827-48. doi: 10.1093/bja/aev371 [MEDLINE]
The Physiologically Difficult Airway. West J Emerg Med. 2015;16(7):1109 [MEDLINE]
The effectiveness of rapid sequence intubation (RSI) versus non-RSI in emergency department: an analysis of multicenter prospective observational study. Int J Emerg Med. 2017;10(1):1 [MEDLINE]
Management of Patients with Predicted Difficult Airways in an Academic Emergency Department. J Emerg Med. 2017;53(2):163 [MEDLINE]
Preoxygenation and Continuous Passive Oxygenation During Apnea (“Apneic Oxygenation”)
Optimizing preoxygenation in adults. Can J Anaesth. 2009 Jun;56(6):449-66 [MEDLINE]
Apneic oxygenation during prolonged laryngoscopy in obese patients: a randomized, controlled trial of nasal oxygen administration. J Clin Anesth. 2010;22(3):164 [MEDLINE]
Preoxygenation with 20ºhead-up tilt provides longer duration of non-hypoxic apnea than conventional preoxygenation in non-obese healthy adults. J Anesth. 2011 Apr;25(2):189-94 [MEDLINE]
Preoxygenation and prevention of desaturation during emergency airway management. Ann Emerg Med. 2012 Mar;59(3):165-75.e1 [MEDLINE]
PREOXYFLOW Trial. High-flow nasal cannula oxygen during endotracheal intubation in hypoxemic patients: a randomized controlled clinical trial. Intensive Care Med. 2015;41(9):1538 [MEDLINE]
Transnasal humidified rapid-insufflation ventilatory exchange (THRIVE): a physiological method of increasing apnoea time in patients with difficult airways. Anaesthesia 2015;70:323-9 [MEDLINE]
Use of high-flow nasal cannula oxygen therapy to prevent desaturation during tracheal intubation of intensive care patients with mild-to-moderate hypoxemia. Crit Care Med. 2015;43:574–583 [MEDLINE]
Apneic oxygenation was associated with decreased desaturation rates during rapid sequence intubation by an Australian helicopter emergency medicine service. Ann Emerg Med. 2015 Apr;65(4):371-6 [MEDLINE]
Randomized Trial of Apneic Oxygenation during Endotracheal Intubation of the Critically Ill. Am J Respir Crit Care Med. 2016;193(3):273 [MEDLINE]
First Pass Success Without Hypoxemia Is Increased With the Use of Apneic Oxygenation During Rapid Sequence Intubation in the Emergency Department. Acad Emerg Med. 2016;23(6):703 [MEDLINE]
High-Flow Nasal Cannula Versus Bag-Valve-Mask for Preoxygenation Before Intubation in Subjects With Hypoxemic Respiratory Failure. Respir Care. 2016;61(9):1160 [MEDLINE]
Pre-oxygenation: Implications in emergency airway management. Am J Emerg Med. 2017;35(8):1177 [MEDLINE]
Respiratory support techniques to avoid desaturation in critically ill patients requiring endotracheal intubation: A systematic review and meta-analysis J Crit Care. 2017 Oct;41:98-106. doi: 10.1016/j.jcrc.2017.05.003 [MEDLINE]
Emergency Department use of Apneic Oxygenation Versus Usual Care During Rapid Sequence Intubation: A Randomized Controlled Trial (The ENDAO Trial). Acad Emerg Med. 2017;24(11):1387 [MEDLINE]
Apneic oxygenation reduces the incidence of hypoxemia during emergency intubation: A systematic review and meta-analysis. Am J Emerg Med. 2017;35(8):1184 [MEDLINE]
Intubation using apnoeic oxygenation to prevent desaturation: A systematic review and meta-analysis. J Crit Care. 2017;41:42 [MEDLINE]
Effectiveness of Apneic Oxygenation During Intubation: A Systematic Review and Meta-Analysis. Ann Emerg Med. 2017;70(4):483 [MEDLINE]
Risk Factors for and Prediction of Hypoxemia during Tracheal Intubation of Critically Ill Adults. Ann Am Thorac Soc. 2018 Nov;15(11):1320-1327. doi: 10.1513/AnnalsATS.201802-118OC [MEDLINE]
Tracheal intubation in critically ill patients: a comprehensive systematic review of randomized trials. Crit Care. 2018 Jan 20;22(1):6. doi: 10.1186/s13054-017-1927-3 [MEDLINE]
PROTRACH Trial. Nasal high-flow preoxygenation for endotracheal intubation in the critically ill patient: a randomized clinical trial. Intensive Care Med. 2019 Apr;45(4):447-458. doi: 10.1007/s00134-019-05529-w [MEDLINE]
PreVent Trial. Bag-Mask Ventilation during Tracheal Intubation of Critically Ill Adults. N Engl J Med. 2019;380(9):811 [MEDLINE]
Cricoid Pressure (Sellick Maneuver)
Best evidence topic report. Cricoid pressure in emergency rapid sequence induction. Emerg Med J. 2005;22(11):815 [MEDLINE]
Laryngeal view during laryngoscopy: a randomized trial comparing cricoid pressure, backward-upward-rightward pressure, and bimanual laryngoscopy. Ann Emerg Med. 2006;47(6):548 [MEDLINE]
Cricoid pressure in emergency department rapid sequence tracheal intubations: a risk-benefit analysis. Ann Emerg Med. 2007;50(6):653 [MEDLINE]
The effect of cricoid pressure on intubation facilitated by the gum elastic bougie. Anaesthesia. 2007;62(5):456 [MEDLINE]
Cricoid pressure results in compression of the postcricoid hypopharynx: the esophageal position is irrelevant. Anesth Analg. 2009 Nov;109(5):1546-52. doi: 10.1213/ane.0b013e3181b05404 [MEDLINE]
Cricoid pressure and laryngeal manipulation in 402 pre-hospital emergency anaesthetics: essential safety measure or a hindrance to rapid safe intubation? Resuscitation. 2010 Jul;81(7):810-6. doi: 10.1016/j.resuscitation.2010.02.023 [MEDLINE]
Accuracy of identification of the cricothyroid membrane in female subjects using palpation: an observational study. Anesth Analg. 2012 May;114(5):987-92. doi: 10.1213/ANE.0b013e31824970ba [MEDLINE]
Videographic analysis of glottic view with increasing cricoid pressure force. Ann Emerg Med. 2013 Apr;61(4):407-13 [MEDLINE]
The effectiveness of cricoid pressure for occluding the esophageal entrance in anesthetized and paralyzed patients: an experimental and observational glidescope study. Anesth Analg. 2014;118(3):580 [MEDLINE]
Effectiveness and risks of cricoid pressure during rapid sequence induction for endotracheal intubation. Cochrane Database Syst Rev. 2015 [MEDLINE]
Effect of Cricoid Pressure Compared With a Sham Procedure in the Rapid Sequence Induction of Anesthesia: The IRIS Randomized Clinical Trial. JAMA Surg. 2019 Jan 1;154(1):9-17. doi: 10.1001/jamasurg.2018.3577 [MEDLINE]
Backward-Upward-Rightward (BURP) Maneuver
Laryngeal view during laryngoscopy: a randomized trial comparing cricoid pressure, backward-upward-rightward pressure, and bimanual laryngoscopy. Ann Emerg Med. 2006;47(6):548 [MEDLINE]
Cricoid pressure and laryngeal manipulation in 402 pre-hospital emergency anaesthetics: essential safety measure or a hindrance to rapid safe intubation? Resuscitation. 2010 Jul;81(7):810-6. doi: 10.1016/j.resuscitation.2010.02.023 [MEDLINE]
A novel bimanual lip extraction and backward, upward, rightward pressure combination for improved laryngoscopy. Am J Emerg Med. 2017 Jan;35(1):177. doi: 10.1016/j.ajem.2016.10.014 [MEDLINE]
Mandibular Advancement
Mandibular advancement improves the laryngeal view during direct laryngoscopy performed by inexperienced physicians. Anesthesiology. 2004 Mar;100(3):598-601 [MEDLINE]
Gum Elastic Bougie
BEAM Trial. Effect of Use of a Bougie vs Endotracheal Tube and Stylet on First-Attempt Intubation Success Among Patients With Difficult Airways Undergoing Emergency Intubation: A Randomized Clinical Trial. JAMA. 2018 Jun 5;319(21):2179-2189. doi: 10.1001/jama.2018.6496 [MEDLINE]
Induction and Paralytic Medications for Rapid Sequence Intubation
Pharmacological properties of ketamine. Drug Alcohol Rev. 1996 Jun;15(2):145-55 [MEDLINE]
KETASED Trial. Etomidate versus ketamine for rapid sequence intubation in acutely ill patients: a multicentre randomised controlled trial. Lancet. 2009 Jul 25;374(9686):293-300. doi: 10.1016/S0140-6736(09)60949-1 [MEDLINE]
Effects of etomidate on complications related to intubation and on mortality in septic shock patients treated with hydrocortisone: a propensity score analysis. Crit Care. 2012 Nov 21;16(6):R224. doi: 10.1186/cc11871 [MEDLINE]
Systematic assessment of dexmedetomidine as an anesthetic agent: a meta-analysis of randomized controlled trials. Arch Med Sci. 2014 Feb 24;10(1):19-24. doi: 10.5114/aoms.2014.40730 [MEDLINE]
Safety of Propofol as an Induction Agent for Urgent Endotracheal Intubation in the Medical Intensive Care Unit. J Intensive Care Med. 2015 Dec;30(8):499-504. doi: 10.1177/0885066614523100 [MEDLINE]
Use of propofol as an induction agent in the acutely injured patient. Eur J Trauma Emerg Surg. 2015 Aug;41(4):405-11. doi: 10.1007/s00068-014-0479-3 [MEDLINE]
Single-dose etomidate does not increase mortality in patients with sepsis: a systematic review and meta-analysis of randomized controlled trials and observational studies. Chest. 2015 Feb;147(2):335-346. doi: 10.1378/chest.14-1012 [MEDLINE]
Single induction dose of etomidate versus other induction agents for endotracheal intubation in critically ill patients. Cochrane Database Syst Rev. 2015 Jan 8;1:CD010225. doi: 10.1002/14651858.CD010225.pub2 [MEDLINE]
Ketamine and propofol combination (“ketofol”) for endotracheal intubations in critically ill patients: a case series. Am J Case Rep. 2015 Feb 13;16:81-6. doi: 10.12659/AJCR.892424 [MEDLINE]
Comparison of Etomidate and Ketamine for Induction During Rapid Sequence Intubation of Adult Trauma Patients. Ann Emerg Med. 2017 Jan;69(1):24-33.e2. doi: 10.1016/j.annemergmed.2016.08.009 [MEDLINE]
Ketamine/propofol admixture vs etomidate for intubation in the critically ill: KEEP PACE Randomized clinical trial. J Trauma Acute Care Surg. 2019 Oct;87(4):883-891. doi: 10.1097/TA.0000000000002448 [MEDLINE]
Paralytic Agents for Rapid Sequence Intubation
Safety and efficacy of sugammadex for the reversal of rocuronium-induced neuromuscular blockade in cardiac patients undergoing noncardiac surgery. Eur J Anaesthesiol. 2009 Oct;26(10):874-84. doi: 10.1097/EJA.0b013e32832c605b [MEDLINE]
Use of sugammadex in patients with a history of pulmonary disease. J Clin Anesth. 2012 Jun;24(4):289-97. doi: 10.1016/j.jclinane.2011.09.006 [MEDLINE]
Neuromuscular blocking agent administration for emergent tracheal intubation is associated with decreased prevalence of procedure-related complications. Crit Care Med. 2012 Jun;40(6):1808-13. doi: 10.1097/CCM.0b013e31824e0e67 [MEDLINE]
Dialysability of sugammadex and its complex with rocuronium in intensive care patients with severe renal impairment. Br J Anaesth. 2012 Sep;109(3):382-90. doi: 10.1093/bja/aes207 [MEDLINE]
Rapid reversal of neuromuscular blockade by sugammadex after continuous infusion of rocuronium in patients with liver dysfunction undergoing hepatic surgery. Acta Anaesthesiol Taiwan. 2014 Jun;52(2):54-8. doi: 10.1016/j.aat.2014.04.007 [MEDLINE]
Neuromuscular blockade improves first-attempt success for intubation in the intensive care unit. A propensity matched analysis. Ann Am Thorac Soc. 2015 May;12(5):734-41. doi: 10.1513/AnnalsATS.201411-517OC [MEDLINE]
Low-Dose or High-Dose Rocuronium Reversed with Neostigmine or Sugammadex for Cesarean Delivery Anesthesia: A Randomized Controlled Noninferiority Trial of Time to Tracheal Intubation and Extubation. Anesth Analg. 2016 May;122(5):1536-45. doi: 10.1213/ANE.0000000000001197 [MEDLINE]
Sugammadex: A Review of Neuromuscular Blockade Reversal. Drugs. 2016 Jul;76(10):1041-52. doi: 10.1007/s40265-016-0604-1 [MEDLINE]
Efficacy and safety of sugammadex versus neostigmine in reversing neuromuscular blockade in adults. Cochrane Database Syst Rev. 2017 Aug 14;8:CD012763. doi: 10.1002/14651858.CD012763 [MEDLINE]
Safety and efficacy of sugammadex for the reversal of rocuronium-induced neuromuscular blockade in cardiac patients undergoing noncardiac surgery. Eur J Anaesthesiol. 2009 Oct;26(10):874-84. doi: 10.1097/EJA.0b013e32832c605b [MEDLINE]
Use of sugammadex in patients with a history of pulmonary disease. J Clin Anesth. 2012 Jun;24(4):289-97. doi: 10.1016/j.jclinane.2011.09.006 [MEDLINE]
Neuromuscular blocking agent administration for emergent tracheal intubation is associated with decreased prevalence of procedure-related complications. Crit Care Med. 2012 Jun;40(6):1808-13. doi: 10.1097/CCM.0b013e31824e0e67 [MEDLINE]
Dialysability of sugammadex and its complex with rocuronium in intensive care patients with severe renal impairment. Br J Anaesth. 2012 Sep;109(3):382-90. doi: 10.1093/bja/aes207 [MEDLINE]
Rapid reversal of neuromuscular blockade by sugammadex after continuous infusion of rocuronium in patients with liver dysfunction undergoing hepatic surgery. Acta Anaesthesiol Taiwan. 2014 Jun;52(2):54-8. doi: 10.1016/j.aat.2014.04.007 [MEDLINE]
Neuromuscular blockade improves first-attempt success for intubation in the intensive care unit. A propensity matched analysis. Ann Am Thorac Soc. 2015 May;12(5):734-41. doi: 10.1513/AnnalsATS.201411-517OC [MEDLINE]
Low-Dose or High-Dose Rocuronium Reversed with Neostigmine or Sugammadex for Cesarean Delivery Anesthesia: A Randomized Controlled Noninferiority Trial of Time to Tracheal Intubation and Extubation. Anesth Analg. 2016 May;122(5):1536-45. doi: 10.1213/ANE.0000000000001197 [MEDLINE]
Sugammadex: A Review of Neuromuscular Blockade Reversal. Drugs. 2016 Jul;76(10):1041-52. doi: 10.1007/s40265-016-0604-1 [MEDLINE]
Efficacy and safety of sugammadex versus neostigmine in reversing neuromuscular blockade in adults. Cochrane Database Syst Rev. 2017 Aug 14;8:CD012763. doi: 10.1002/14651858.CD012763 [MEDLINE]
Delayed Sequence Intubation (DSI)
Delayed sequence intubation: a prospective observational study. Ann Emerg Med. 2015;65(4):349 [MEDLINE]
Awake Laryngoscopy
Endotracheal intubation in the ICU. Crit Care. 2015;19:258 [MEDLINE]
Awake Laryngoscopy in the Emergency Department. J Emerg Med. 2017;52(3):324 [MEDLINE]
Video Laryngoscopy
Videolaryngoscopy with glidescope reduces cervical spine movement in patients with unsecured cervical spine. J Emerg Med. 2013 Apr;44(4):750-6 [MEDLINE]
Video laryngoscopy versus direct laryngoscopy for orotracheal intubation in the intensive care unit: a systematic review and meta-analysis. Intensive Care Med. 2014 May;40(5):629-39. doi: 10.1007/s00134-014-3236-5 [MEDLINE]
Comparison of video laryngoscopy versus direct laryngoscopy during urgent endotracheal intubation: a randomized controlled trial. Crit Care Med. 2015;43(3):636 [MEDLINE]
Predictors of difficult videolaryngoscopy with GlideScope® or C-MAC® with D-blade: secondary analysis from a large comparative videolaryngoscopy trial. Br J Anaesth. 2016 Jul;117(1):118-23. doi: 10.1093/bja/aew128 [MEDLINE]
Difficult Airway Characteristics Associated with First-Attempt Failure at Intubation Using Video Laryngoscopy in the Intensive Care Unit. Ann Am Thorac Soc. 2017 Mar;14(3):368-375. doi: 10.1513/AnnalsATS.201606-472OC [MEDLINE]
Video Laryngoscopy vs Direct Laryngoscopy on Successful First-Pass Orotracheal Intubation Among ICU Patients: A Randomized Clinical Trial. JAMA. 2017 Feb 7;317(5):483-493. doi: 10.1001/jama.2016.20603 [MEDLINE]
A practice survey of airway management in Australian and New Zealand intensive care units. Crit Care Resusc. 2019 Jun;21(2):139-147 [MEDLINE]
Preventing unrecognised oesophageal intubation: a consensus guideline from the Project for Universal Management of Airways and international airway societies. Anaesthesia. 2022 Dec;77(12):1395-1415. doi: 10.1111/anae.15817 [MEDLINE]
Confirmation of Endotracheal Tube Placement
Accidental intubation of the oesophagus. Anaesth Intensive Care. 1980;8(2):183 [MEDLINE]
End-tidal CO2 as a guide to successful cardiopulmonary resuscitation: a preliminary report. Crit Care Med. 1985;13(11):910 [MEDLINE]
Esophageal intubation: a review of detection techniques. Anesth Analg. 1986;65(8):886 [MEDLINE]
Unrecognized endobronchial intubation of emergency patients. Ann Emerg Med. 1989;18(8):853 [MEDLINE]
A comparative study of methods of detection of esophageal intubation. Anesth Analg. 1989;69(5):627 [MEDLINE]
Multicenter study of a portable, hand-size, colorimetric end-tidal carbon dioxide detection device. Ann Emerg Med. 1992 May;21(5):518-23 [MEDLINE]
Women are at greater risk than men for malpositioning of the endotracheal tube after emergent intubation. Crit Care Med. 1994;22(7):1127 [MEDLINE]
Proper depth placement of oral endotracheal tubes in adults prior to radiographic confirmation. Acad Emerg Med. 1995;2(1):20 [MEDLINE]
Use of tube condensation as an indicator of endotracheal tube placement. Ann Emerg Med. 1998;31(5):575 [MEDLINE]
Comparison of three different methods to confirm tracheal tube placement in emergency intubation. Intensive Care Med. 2002;28(6):701 [MEDLINE]
Towards evidence based emergency medicine: best BETs from the Manchester Royal Infirmary. Colourimetric CO(2) detector compared with capnography for confirming ET tube placement. Emerg Med J. 2003 May;20(3):265-6 [MEDLINE]
The assessment of three methods to verify tracheal tube placement in the emergency setting. Resuscitation 2003; 56:153-157 [MEDLINE]
An assessment of a tracheal tube introducer as an endotracheal tube placement confirmation device. Am J Emerg Med. 2005;23(6):754 [MEDLINE]
Caution when using colorimetry to confirm endotracheal intubation. Anesth Analg 2007;104:738 [MEDLINE]
Endobronchial intubation detected by insertion depth of endotracheal tube, bilateral auscultation, or observation of chest movements: randomised trial. BMJ. 2010;341:c5943 [MEDLINE]
Ultrasonography in the management of the airway. Acta Anaesthesiol Scand. 2011 Nov;55(10):1155-73. Epub 2011 Sep 7 [MEDLINE]
Tracheal rapid ultrasound exam (T.R.U.E.) for confirming endotracheal tube placement during emergency intubation. Resuscitation. 2011 Oct;82(10):1279-84. Epub 2011 Jun 1 [MEDLINE]
Transtracheal ultrasound for verification of endotracheal tube placement: a systematic review and meta-analysis. Can J Anaesth. 2015 Apr;62(4):413-23. Epub 2014 Dec 24 [MEDLINE]
Ultrasonography for confirmation of endotracheal tube placement: a systematic review and meta-analysis. Resuscitation. 2015;90:97 [MEDLINE]
Auscultation versus Point-of-care Ultrasound to Determine Endotracheal versus Bronchial Intubation: A Diagnostic Accuracy Study. Anesthesiology. 2016 May;124(5):1012-20 [MEDLINE]
Endotracheal Tube Movement with Change in Head Position
Alteration of endotracheal tube position. Flexion and extension of the neck. Crit Care Med. 1976 Jan-Feb;4(1):8-12 [MEDLINE]
Laryngeal Mask Airway (LMA)
Effect of the laryngeal mask airway on lower oesophageal sphincter pressure in patients during general anaesthesia. Br J Anaesth. 1992 Oct;69(4):346-8 [MEDLINE]
Clinical significance of pulmonary aspiration during the perioperative period. Anesthesiology. 1993;78(1):56 [MEDLINE]
The incidence of aspiration associated with the laryngeal mask airway: a meta-analysis of published literature. J Clin Anesth. 1995;7(4):297 [MEDLINE]
Gastric regurgitation during general anaesthesia in different positions with the laryngeal mask airway. Anaesthesia. 1995 Dec;50(12):1053-5 [MEDLINE]
Survey of laryngeal mask airway usage in 11,910 patients: safety and efficacy for conventional and nonconventional usage. Anesth Analg. 1996 Jan;82(1):129-33 [MEDLINE]
Gastroesophageal reflux during spontaneous respiration with the laryngeal mask airway. Can J Anaesth. 1999 Mar;46(3):268-70 [MEDLINE]
ProSeal laryngeal mask protects against aspiration of fluid in the pharynx. Br J Anaesth. 2002 Apr;88(4):584-7 [MEDLINE]
Aspiration and the laryngeal mask airway: three cases and a review of the literature. Br J Anaesth. 2004 Oct;93(4):579-82 [MEDLINE]
The Proseal LMA is a useful rescue device during failed rapid sequence intubation: two additional cases. Can J Anaesth. 2005 Jun;52(6):630-3 [MEDLINE]
Use of manometry for laryngeal mask airway reduces postoperative pharyngolaryngeal adverse events: a prospective, randomized trial. Anesthesiology. 2010 Mar;112(3):652-7 [MEDLINE]
Major complications of airway management in the UK: results of the Fourth National Audit Project of the Royal College of Anaesthetists and the Difficult Airway Society. Part 1: anaesthesia. Br J Anaesth. 2011 May;106(5):617-31 [MEDLINE]
Major complications of airway management in the UK: results of the Fourth National Audit Project of the Royal College of Anaesthetists and the Difficult Airway Society. Part 2: intensive care and emergency departments. Br J Anaesth. 2011;106(5):632 [MEDLINE]
Can we make airway management (even) safer?–lessons from national audit. Anaesthesia. 2011;66 Suppl 2:27 [MEDLINE]
New supraglottic airway with built-in pressure indicator decreases postoperative pharyngolaryngeal symptoms: a randomized controlled trial. Can J Anaesth. 2013 Dec;60(12):1197-203 [MEDLINE]
Feasibility of a laryngeal tube for airway management during cardiac arrest by first responders. Resuscitation. 2013;84(4):446 [MEDLINE]
Supraglottic airway devices versus tracheal intubation for airway management during general anaesthesia in obese patients. Cochrane Database Syst Rev. 2013 [MEDLINE]
Airway management by physician-staffed Helicopter Emergency Medical Services – a prospective, multicentre, observational study of 2,327 patients. Scand J Trauma Resusc Emerg Med. 2015;23:57 [MEDLINE]
Safety and feasibility of the laryngeal tube when used by EMTs during out-of-hospital cardiac arrest. Am J Emerg Med. 2015;33(8):1050 [MEDLINE]
Effect of a Strategy of Initial Laryngeal Tube Insertion vs Endotracheal Intubation on 72-Hour Survival in Adults With Out-of-Hospital Cardiac Arrest: A Randomized Clinical Trial. JAMA. 2018;320(8):769 [MEDLINE]
Effect of a Strategy of a Supraglottic Airway Device vs Tracheal Intubation During Out-of-Hospital Cardiac Arrest on Functional Outcome: The AIRWAYS-2 Randomized Clinical Trial. JAMA. 2018;320(8):779 [MEDLINE]
Cricothyrotomy in the emergency department. Ann Emerg Med. 1982;11(7):361 [MEDLINE]
Cricothyrotomy in the emergency department revisited. J Emerg Med. 1989;7(2):115 [MEDLINE]
Prehospital cricothyrotomy: an investigation of indications, technique, complications, and patient outcome. Ann Emerg Med. 1990;19(3):279 [MEDLINE]
Declining rate of cricothyrotomy in trauma patients with an emergency medicine residency: implications for skills training. Acad Emerg Med. 1998;5(3):247 [MEDLINE]
Comparison of 2 cricothyrotomy techniques: standard method versus rapid 4-step technique. Ann Emerg Med. 1998;32(4):442 [MEDLINE]
Outcomes of emergency surgical airway procedures in a hospital-wide setting. Laryngoscope. 1999;109(11):1766 [MEDLINE]
Comparison of wire-guided cricothyrotomy versus standard surgical cricothyrotomy technique. J Emerg Med. 1999;17(6):957 [MEDLINE]
Cricothyroidotomy: when, why, and why not? Am J Otolaryngol. 2000;21(3):195 [MEDLINE]
Cricothyrotomy: a 5-year experience at one institution. J Emerg Med. 2003;24(2):151 [MEDLINE]
[Emergency cricothyrotomy–puncture or anatomical preparation? Peculiarities of two methods for emergency airway access demonstrated in a cadaver model]. Anaesthesist. 2003;52(4):304 [MEDLINE]
Needle vs surgical cricothyroidotomy: a short cut to effective ventilation. Anaesthesia. 2006;61(10):962[MEDLINE]
A comparison of two emergency cricothyroidotomy kits in human cadavers. Anesth Analg. 2008;106(1):182 [MEDLINE]
Accuracy of surface landmark identification for cannula cricothyroidotomy. Anaesthesia. 2010;65(9):889 [MEDLINE]
Accuracy of identification of the cricothyroid membrane in female subjects using palpation: an observational study. Anesth Analg. 2012 May;114(5):987-92 [MEDLINE]
Accuracy of conventional digital palpation and ultrasound of the cricothyroid membrane in obese women in labour. Anaesthesia. 2015 Nov;70(11):1230-4 [MEDLINE]
Comparing success rates of anesthesia providers versus trauma surgeons in their use of palpation to identify the cricothyroid membrane in female subjects: a prospective observational study. Can J Anaesth. 2016 Jul;63(7):807-817 [MEDLINE]
Adverse Effects/Complications
Ulcerative tracheo-oesophageal fistula during treatment by tracheostomy and intermittent positive pressure ventilation. Thorax. 1972;27(3):338 [MEDLINE]
Tracheal injury following prolonged intubation. Aust N Z J Surg. 1976 Feb;46(1):18-25 [MEDLINE]
Intubation lesions of the larynx. Br J Anaesth. 1978;50(6):587 [MEDLINE]
Postoperative sore throat: influence of tracheal tube lubrication versus cuff design. Can Anaesth Soc J. 1980;27(2):156 [MEDLINE]
Laryngeal injuries secondary to nasogastric tubes. Ann Otol Rhinol Laryngol. 1981;90(5 Pt 1):469 [MEDLINE]
The influence of endotracheal tube cuff design and cuff lubrication on postoperative sore throat. Anesthesiology. 1983;58(4):376 [MEDLINE]
Laryngotracheal injury due to endotracheal intubation: incidence, evolution, and predisposing factors. A prospective long-term study. Crit Care Med. 1983;11(5):362 [MEDLINE]
True vocal cord paralysis following intubation. Laryngoscope. 1985;95(11):1352 [MEDLINE]
Correlation of endotracheal tube size with sore throat and hoarseness following general anesthesia. Anesthesiology. 1987 Sep;67(3):419-21 [MEDLINE]
Laryngeal complications of prolonged intubation. Chest. 1989;96(4):877 [MEDLINE]
Anesthesia-induced dental injury. Int Anesthesiol Clin. 1989;27(2):120 [MEDLINE]
Unsuspected cervical fractures: a common problem in ankylosing spondylitis. Anesthesiology. 1989;70(5):869 [MEDLINE]
Tracheoesophageal fistula formation in intubated patients. Risk factors and treatment with high-frequency jet ventilation. Chest. 1990;98(1):161 [MEDLINE]
Swallowing disorders in patients with prolonged orotracheal intubation or tracheostomy tubes. Crit Care Med. 1990;18(12):1328 [MEDLINE]
Adverse respiratory events infrequently leading to malpractice suits. A closed claims analysis. Anesthesiology. 1991;75(6):932 [MEDLINE]
Surgical considerations in tracheal stenosis. Laryngoscope. 1992 Mar;102(3):237-43 [MEDLINE]
Resolution of laryngeal injury following translaryngeal intubation. Am Rev Respir Dis. 1992;145(2 Pt 1):361 [MEDLINE]
Evaluation of risk factors for laryngeal edema after tracheal extubation in adults and its prevention by dexamethasone. A placebo-controlled, double-blind, multicenter study. Anesthesiology. 1992;77(2):245 [MEDLINE]
Massive airway leaks: an analysis of the role of endotracheal tubes. Crit Care Med. 1993;21(4):518 [MEDLINE]
Mediastinitis and sepsis syndrome following intubation. Anaesthesia. 1994;49(10):883 [MEDLINE]
Risk factors associated with prolonged intubation and laryngeal injury. Otolaryngol Head Neck Surg. 1994;111(4):453 [MEDLINE]
[A survey of perioperative bronchospasm in 105 patients with reactive airway disease]. Masui. 1995;44(3):396 [MEDLINE]
Management of acquired tracheoesophageal fistula. Chest Surg Clin N Am. 1996 Nov;6(4):819-36 [MEDLINE]
Gastroesophageal reflux in patients with subglottic stenosis. Arch Otolaryngol Head Neck Surg. 1998 May;124(5):551-5 [MEDLINE]
Airway injury during anesthesia: a closed claims analysis. Anesthesiology. 1999;91(6):170 [MEDLINE]
Postextubation fiberoptic endoscopic evaluation of swallowing after prolonged endotracheal intubation: a randomized, prospective trial. Crit Care Med. 2001;29(9):1710 [MEDLINE]
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Association of Number of Physician Postgraduate Years With Patient Intubation Outcomes in the Emergency Department. JAMA Netw Open. 2022 Apr 1;5(4):e226622. doi: 10.1001/jamanetworkopen.2022.6622 [MEDLINE]
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