Rapid Sequence Intubation (RSI)

Definition and Background

• Rapid Sequence Intubation Utilizes a Period of Preoxygenation, Followed by the Nearly Simultaneous Administration of a Sedative Induction Agent and a Paralytic Agent to Facilitate Rapid and Effective Endotracheal Intubation (with a Minimal Risk of Aspiration)
  • Rapid Sequence Intubation is the Most Common Emergency Intubation Technique in a Patient Who is Not Anticipated to Have a Difficult Airway (Ann Emerg Med, 2015) [MEDLINE]
  • Approximately 85% of First Endotracheal Intubation Attempts in Emergency Departments are Performed Using Rapid Sequence Intubation (Ann Emerg Med, 2015) [MEDLINE]
  • Rapid Sequence Intubation Decreases Procedure-Related Complications and Increases 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]
  • Rapid Sequence Intubation Has High First-Pass Endotracheal Intubation Success Rates with Video Laryngoscopy (90%) in Patients with Anticipated Difficult Airways (J Emerg Med, 2017) [MEDLINE]:
    • Only 11% of Non-Cardiac Arrest Patients Had a Predicted Difficult Airway in this Study and None Required a Surgical Airway (J Emerg Med, 2017) [MEDLINE]
• Relative Contraindications to Rapid Sequence Intubation
  • Anticipated Difficult Intubation (Especially if Rescue is Anticipated to Be Difficult or Impossible)
  • Inability to Tolerate the Apneic Period During Rapid Sequence Intubation (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
• Effect on Obesity on Apneic Time (see Obesity)
  • 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]

Body Positioning

• Society of Critical Care Medicine Clinical Practice Guidelines for Rapid Sequence Intubation in the Critically Ill Adult Patient (2023) (Crit Care Med, 2023) [MEDLINE]
  • Use of Head and Torso Inclined (Semi-Fowler) Position is Recommended During Rapid Sequence Intubation (Conditional Recommendation, Very Low Quality of Evidence)
    • While Rapid Sequence Intubation Has Traditionally Been Performed with the Patient in Neck Flexion and Head Extension (“Sniffing Position”) or Neutral Head and Neck Position (if There is a Concern for Cervical Spine Injury) Together with the Torso Parallel with the Head and Neck
    • However, Recent Studies Suggest that a Head and Trunk Inclined (Semi-Fowler) Position May Improve First-Pass Success Through Enhanced Preoxygenation (Denitrogenation) Via Increased Functional Residual Capacity (FRC) and Improved Laryngeal View, and Decrease the Risk of Clinically Significant Aspiration of Passively Regurgitated Gastric Contents

Nasogastric Tube Decompression (see Nasogastric-Orogastric Tube)

• Society of Critical Care Medicine Clinical Practice Guidelines for Rapid Sequence Intubation in the Critically Ill Adult Patient (2023) (Crit Care Med, 2023) [MEDLINE]
  • Nasogastric Tube Decompression is Recommended When the Benefit Outweighs the Risk in Patients Who are Undergoing Rapid Sequence Intubation and are at High Risk of Regurgitation of Gastric Contents

Peri-intubation Vasopressors

• Society of Critical Care Medicine Clinical Practice Guidelines for Rapid Sequence Intubation in the Critically Ill Adult Patient (2023) (Crit Care Med, 2023) [MEDLINE]
  • Peri-Intubation Hypotension is Associated with Increased Intensive Care Unit Mortality (JAMA, 2021) [MEDLINE]
  • There is Insufficient Evidence to Make a Recommendation Regarding a Difference in the Incidence of Further Hypotension or Post-Intubation Cardiac Arrest Between the Administration of Peri-Intubation Vasopressors or Intravenous Fluids for Hypotensive Critically Ill Patients Undergoing Rapid Sequence Intubation (Insufficient Evidence)

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
• Society of Critical Care Medicine Clinical Practice Guidelines for Rapid Sequence Intubation in the Critically Ill Adult Patient (2023) (Crit Care Med, 2023) [MEDLINE]
  • Preoxygenation with High-Flow Nasal Cannula is Recommended When Laryngoscopy is Expected to Be Challenging (Conditional Recommendation, Low Quality of Evidence)
    • Critically Ill Patients are at High Risk of Experiencing Desaturation, Particularly During Prolonged Intubations
      • Therefore, Preoxygenation is Required to Prolong the Duration of Apnea without Desaturation (“Safe Apnea Time”)
    • High-Flow Nasal Cannula Does Not Appear to Affect Aspiration Risk (Low Quality Evidence)
  • Preoxygenation with Noninvasive Positive-Pressure Ventilation is Recommended in Patients with Severe Hypoxemia pO2/FiO2 <150 (Conditional Recommendation, Low Quality of Evidence)
    • Critically Ill Patients are at High Risk of Experiencing Desaturation, Particularly During Prolonged Intubations
      • Therefore, Preoxygenation is Required to Prolong the Duration of Apnea without Desaturation (“Safe Apnea Time”)
    • In Patients with Severe Hypoxemia, Noninvasive Positive-Pressure Ventilation Appears to Have the Strongest Evidence for Decreasing the Incidence of Critical Desaturation During Rapid Sequence Intubation
      • However, Noninvasive Positive-Pressure Ventilation Requires Removal During Laryngoscopy (While High-Flow Nasal Cannula Does Not)
  • Medication-Assisted Preoxygenation (“Delayed Sequence Intubation”) to Improve Preoxygenation is Recommended in Patients Undergoing Rapid Sequence Intubation Who are Not Able to Tolerate a Face Mask, Noninvasive Positive-Pressure Ventilation, or High-Flow Nasal Cannula Because of Agitation, Delirium, or Combative Behavior (Conditional Recommendation, Very Low Quality of Evidence)
    • To Achieve This, the Sedative-Hypnotic Agent is Administered to Facilitate Preoxygenation and Once the Clinician is Satisfied that the Patient is Adequately Preoxygenated, then the Neuromuscular Junction Antagonist is Administered, Followed by Intubation

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
• 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
• 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]
  • 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
  • BEAM Randomized Trial of Gum Elastic Bougie vs Endotracheal Tube and Stylet in Difficult Emergency Intubation in the Emergency Department (JAMA, 2018) [MEDLINE]: n = 757
    • Among All Patients, Gum Elastic Bougie Increased First-Pass Success Rate in Emergency Intubation (98%), as Compared to Endotracheal Tube and Stylet (87%) (Absolute Between-Group Difference, 11%; 95% CI: 7%-14%])
    • Among the 380 Patients with at Least 1 Difficult Airway Characteristic, Gum Elastic Bougie Increased First-Pass Success Rate in Emergency Intubation (96%), as Compared to Endotracheal Tube and Stylet (82%) (Absolute Between-Group Difference, 14%; 95% CI: 8%-20%])
    • Median Duration of the First Intubation Attempt (38 sec vs 36 sec) and the Incidence of Hypoxemia (13% vs 14%) Did Not Differ Significantly Between the Gum Elastic Bougie vs Endotracheal Tube and Stylet Groups

Induction Medications for Rapid Sequence Intubation (RSI)

• Etomidate (Amidate) (see Etomidate)
  • Pharmacology
    • GABA Potentiation
    • Onset: 30-60 sec
    • Duration: 3-5 min
  • Properties
    • Excellent Sedation
    • No/Minimal Effect on Respiratory Rate
    • Decrease in Intracranial Pressure (see Increased Intracranial Pressure)
    • Decrease in Cerebral Blood Flow
    • Decrease in Cerebral Metabolic Rate of Oxygen
  • Administration
    • Load (IV Induction for Intubation): 0-2-0.3 mg/kg IVP (Usual Dose: 10-20 mg)
  • Adverse Effects
    • Adrenal Suppression (see Adrenal Insufficiency): this side effect has created ongoing concern about the use of etomidate for induction for endotracheal intubation in critically ill patients
    • Minimal Hypotension (see Hypotension)
  • Clinical Efficacy
    • In the KETASED Multicenter, Randomized Trial of Etomidate vs Ketamine for Intubation of Acutely Ill Patients, Ketamine was a Safe Alternative to Etomidate for Endotracheal Intubation (Although the Percentage of Patients with Adrenal Insufficiency was Significantly Higher in the Etomidate Group) (Lancet, 2009) [MEDLINE]
    • In a Propensity Score Analysis of Etomidate in Patients with Septic Shock Treated with Hydrocortisone, Etomidate Did Not Impact Life-Threatening Complications Following Intubation, But When Associated with Hydrocortisone, it Also Did Not Worsen Outcome (Crit Care, 2012) [MEDLINE]
    • In Retrospective Trauma Study Using Propofol as an Induction Agent for Rapid Sequence Intubation, Propofol Did Not Result in Hypotension (Mean Dose: 127 ± 5 mg), as Compared to Etomidate (Mean Dose: 21 ± 6 mg) (Eur J Trauma Emerg Surg, 2015) [MEDLINE]
    • In a Systematic Review and Meta-Analysis of Mostly Retrospective/Observational Studies of Single-Dose Etomidate for Endotracheal Intubation in Patients with Sepsis, Etomidate Did Not Increase the Mortality Rate (Chest, 2015) [MEDLINE]
    • In a Cochrane Database Systematic Review of Single-Dose Etomidate for Induction for Endotracheal Intubation, There was No Conclusive Evidence that Etomidate Increased the Mortality Rate or Healthcare Resource Utilization in Critically Ill Patients (But Did Increase the Risk of Adrenal Dysfunction and Multiorgan System Dysfunction by a Small Amount) (Cochrane Database Syst Rev, 2015) [MEDLINE]
    • In a Comparison of Etomidate and Ketamine for Induction During Rapid Sequence Intubation of Adult Trauma Patients, Patient-Centered Outcomes were Comparable for Either Agent (Ann Emerg Med, 2017) [MEDLINE]
    • In the KEEP PACE Randomized Trial of Ketamine/Propofol vs Decreased-Dose Etomidate for Induction Prior to Endotracheal Intubation of Critically Ill Patients, Ketamine/Propofol Admixture (0.5 mg/kg of Ketamine and Propofol Each) was Comparable to Decreased Dose Etomidate (0.15 mg/kg) in Terms of Maintaining Mean Arterial Blood Pressure, Use of Vasopressors, and Difficulty of Intubation (J Trauma Acute Care Surg, 2019) [MEDLINE]
    • In a Meta-Analysis of Etomidate for Induction Prior to Endotracheal Intubation (n = 2,704. 11 Trials), Etomidate Increased the Mortality Rate 23% vs 20% (Risk Ratio 1.16; 95% CI: 1.01-1.33; P = 0.03; I2 = 0%; Number Needed to Harm = 31) (J Crit Care, 2023) [MEDLINE]
• Ketamine (Ketalar) (see Ketamine)
  • Pharmacology
    • NMDA Antagonist (Drug Alcohol Rev, 1996) [MEDLINE]
    • Onset: 30-60 sec
    • Half-Life (Alpha): 10-15 min
    • Duration (Anesthetic Effect): 45 min (recovery within 1-2 hrs)
  • Properties
    • Amnestic Effect (see Amnesia)
    • Analgesic Effect
    • Bronchodilation
    • Dissociative Sedative Effect
    • Does Not Inhibit Protective Reflexes
    • Increase in Circulating Norepinephrine
    • Minimal Respiratory Depression
    • Increase in Intracranial Pressure (see Increased Intracranial Pressure)
    • Increase in Cerebral Blood Flow
    • Small Increase in Cerebral Metabolic Rate of Oxygen
  • Administration
    • Load (IV Induction for Intubation): 0.5-2.0 mg/kg (usual adult dose: 100 mg, slow push over 1-2 min)
    • Load (IV for ICU Sedation): 0.1-0.5 mg/kg
    • Maintenance (IV): 0.05-0.4 mg/kg/hr (Crit Care Med, 2013) [MEDLINE]
  • Adverse Effects
    • Anaphylaxis (see Anaphylaxis)
    • Arrhythmias: occurs in some cases
    • Bradycardia: occurs in some cases
    • Diplopia (see Diplopia): may occur in some cases
    • Emergence Reactions (Delirium, Hallucinations, Irrational Behavior, etc): occur in 12% of cases
    • Enhanced Pressor Response: may occur with rapid administration
    • Fasciculations (see Fasciculations): may occur in some cases
    • Hypertension (see Hypertension): typically occurs shortly after injection (and returns to normal within 15 min)
    • Hyporeflexia (see Hyporeflexia): may occur in some cases
    • Hypotension (see Hypotension): occurs in some cases
    • Increased Intracranial Pressure (see Increased Intracranial Pressure): may occur in some cases
    • Increased Intraocular Pressure: may occur in some cases
    • Laryngospasm (see Laryngospasm)
    • Local Injection Site Pain: has been reported
    • Myocardial Depression: may occur in some cases
    • Nausea/Vomiting (see Nausea and Vomiting): usually not severe or prolonged
    • Nystagmus (see Nystagmus): may occur in some cases
    • Respiratory Depression (see Acute Hypoventilation): may occur with rapid administration or overdosage
    • Sympathetic Stimulation
    • Sialorrhea (Hypersalivation) (see Sialorrhea)
    • Tachycardia (see Sinus Tachycardia)
    • Tonic-Clonic Movements (Seizure-Like): may occur in some cases (due to enhanced muscle tone)
    • Transient Erythema/Morbilliform Rash: has been reported
  • Clinical Efficacy
    • In the KETASED Multicenter, Randomized Trial of Etomidate vs Ketamine for Intubation of Acutely Ill Patients, Ketamine was a Safe Alternative to Etomidate for Endotracheal Intubation (Although the Percentage of Patients with Adrenal Insufficiency was Significantly Higher in the Etomidate Group) (Lancet, 2009) [MEDLINE]
    • In Small Case Series, Ketamine and Propofol (“Ketofol”) Can Be Used as Induction Agents for Intubation of Hemodynamically-Unstable Critically Ill Patients (Am J Case Rep, 2015) [MEDLINE]
    • In a Comparison of Etomidate and Ketamine for Induction During Rapid Sequence Intubation of Adult Trauma Patients, Patient-Centered Outcomes were Comparable for Either Agent (Ann Emerg Med, 2017) [MEDLINE]
    • In the KEEP PACE Randomized Trial of Ketamine/Propofol vs Decreased-Dose Etomidate for Induction Prior to Endotracheal Intubation of Critically Ill Patients, Ketamine/Propofol Admixture (0.5 mg/kg of Ketamine and Propofol Each) was Comparable to Decreased Dose Etomidate (0.15 mg/kg) in Terms of Maintaining Mean Arterial Blood Pressure, Use of Vasopressors, and Difficulty of Intubation ( J Trauma Acute Care Surg, 2019) [MEDLINE]
• Midazolam (Versed) (see Midazolam)
  • Pharmacology
    • Benzodiazepine (see Benzodiazepines)
    • Onset: 30-60 sec
    • Duration: 3-11 hrs (Typical Range: 1.8-6.4 hrs)
    • Prolonged Infusion Results in Accumulation of the Active Metabolite
    • Half-Life is Prolonged in Cirrhosis, Congestive Heart Failure, Obesity, Renal Failure, and the Elderly
  • Properties
    • Amnestic Effect (see Amnesia)
    • Anxiolytic Effect
    • Increases Seizure Threshold
    • Dose-Related Myocardial Depression (May Result in Hypotension)
    • Sedative Effect
    • No Analgesic Effect
    • No/Minimal Effect on Heart Rate
    • Respiratory Depression (see Respiratory Failure)
    • Decrease in Intracranial Pressure (see Increased Intracranial Pressure)
    • Decrease in Cerebral Blood Flow
    • Decrease in Cerebral Metabolic Rate of Oxygen
  • Administration
    • Load (IV Induction for Intubation): 2-10 mg IVP
    • Maintenance (IV): 1-10 mg/hr
  • Adverse Effects
    • Hypotension (see Hypotension)
    • Respiratory Depression (see Acute Hypoventilation)
• Propofol (Diprivan) (see Propofol)
  • Pharmacology: GABA potentiation
    • Other Pharmacologic Effects: effect on glutamate receptors, effect on cannabinoid receptors, and sodium channel blocking effects
    • Onset: 9-51 sec (usual: 30 sec)
    • Duration (with Bolus Dose): 3-10 min
    • Half-Life (with Infusion): 30-60 min (longer half-life is observed with prolonged infusion, however, the duration of the clinical effect is typically minutes, as propofol is rapidly distributed into peripheral tissues)
  • Properties
    • Amnestic Effect (see Amnesia)
    • Anti-Emetic Effect
    • Anxiolytic Effect
    • Increases Seizure Threshold
    • Sedative Effect
    • Myocardial Depression
    • No Analgesic Effect
    • Respiratory Depression (see Respiratory Failure)
    • Large Lipid Load: requiring adjustment of enteral/parenteral nutritional support
    • Decrease in Intracranial Pressure (see Increased Intracranial Pressure)
    • Decrease in Cerebral Blood Flow
    • Decrease in Cerebral Metabolic Rate of Oxygen
  • Administration
    • Load (IV Induction for Intubation, Healthy, <55 y/o Patients): 2-2.5 mg/kg (given as 40 mg q10 min)
    • Load (IV Induction for Elderly, Debilitated Patients): 1-1.5 mg/kg (given as 20 mg q10 min)
    • Maintenance (IV): 10-60 μg/kg/min
  • Adverse Effects
    • Dystonia (see Dystonia)
    • Hypertriglyceridemia (see Hypertriglyceridemia)
    • Hypotension (Dose-Related) (see Hypotension)
    • Injection Site Pain
    • Myocardial Depression
    • Priapism (see Priapism)
    • Propofol Infusion Syndrome: may occur at high doses (more commonly occurs in children)
    • Respiratory Depression (see Acute Hypoventilation)
    • Sinus Bradycardia (see Sinus Bradycardia)
  • Clinical Efficacy
    • Study of the Safety of Propofol as an Induction Agent (Using 0.5-1.0 mg/kg as the Initial Dose, Average Dose of Propofol: 99 mg, SD ± 7.39) for Urgent Endotracheal Intubation in the ICU Demonstrated Hypotension in Only 4% of Cases (Concomitant Vasopressors were Used in 59% of Cases) (J Intensive Care Med, 2015) [MEDLINE]
    • In Retrospective Trauma Study Using Propofol as an Induction Agent for Rapid Sequence Intubation, Propofol Did Not Result in Hypotension (Mean Dose: 127 ± 5 mg), as Compared to Etomidate (Mean Dose: 21 ± 6 mg) (Eur J Trauma Emerg Surg, 2015) [MEDLINE]
    • In Small Case Series, Ketamine and Propofol (“Ketofol”) Can Be Used as Induction Agents for Intubation of Hemodynamically-Unstable Critically Ill Patients (Am J Case Rep, 2015) [MEDLINE]
    • In the KEEP PACE Randomized Trial of Ketamine/Propofol vs Decreased-Dose Etomidate for Induction Prior to Endotracheal Intubation of Critically Ill Patients, Ketamine/Propofol Admixture (0.5 mg/kg of Ketamine and Propofol Each) was Comparable to Decreased Dose Etomidate (0.15 mg/kg) in Terms of Maintaining Mean Arterial Blood Pressure, Use of Vasopressors, and Difficulty of Intubation ( J Trauma Acute Care Surg, 2019) [MEDLINE]
• Society of Critical Care Medicine Clinical Practice Guidelines for Rapid Sequence Intubation in the Critically Ill Adult Patient (2023) (Crit Care Med, 2023) [MEDLINE]
  • In Critically Ill Adults with Hemodynamic Instability and Depressed Level of Consciousness Who are Undergoing Endotracheal Intubation, Administration of a Sedative-Hypnotic Induction Agent is Recommended When a Neuromuscular Junction Antagonist is Used for Intubation
  • There is No Difference Between Etomidate and Other Induction Agents Administered for Rapid Sequence Intubation with Respect to Mortality or the Incidence of Hypotension or Vasopressor Use in the Peri-Intubation Period and Through Hospital Discharge (Conditional Recommendation, Moderate Quality of Evidence)
  • Administration of Corticosteroids is Not Recommended Following Rapid Sequence Intubation with Etomidate for the Purpose of Counteracting Etomidate-Induced Adrenal Suppression (Conditional Recommendation, Low Quality of Evidence)

Neuromuscular Junction Antagonist Medications for Rapid Sequence Intubation (RSI)

• Succinylcholine (see Succinylcholine)
  • Pharmacology
    • Depolarizing Neuromuscular Junction Antagonist (see Neuromuscular Junction Antagonists)
    • Dose (Intravenous): 1.5 mg/kg IV push
    • Onset of Intubation-Level Paralysis: 45-60 sec (Anesth Analg, 2006) [MEDLINE]
    • Duration of Paralysis: 6-10 min (Anesth Analg, 2006) [MEDLINE]
• Rocuronium (Zemuron) (see Rocuronium)
  • Pharmacology
    • Non-Depolarizing Neuromuscular Junction Antagonist (see Neuromuscular Junction Antagonists)
    • Dose (Intravenous):: 0.6-1.2 mg/kg IV push
    • Onset of Intubation-Level Paralysis (with Dose 1-1.2 mg/kg Ideal Body Weight): 45-60 sec
      • However, in the Emergency Setting, Clinicians Frequently Estimate Patient Body Weight Incorrectly (Emerg Med Australas, 2005) [MEDLINE] (Spartan Med Res J, 2017) [MEDLINE]
    • Duration: 45 min
• Vecuronium (Norcuron) (see Vecuronium)
  • Pharmacology
    • Non-Depolarizing Neuromuscular Junction Antagonist (see Neuromuscular Junction Antagonists)
    • Onset of Intubation-Level Paralysis (When Using a 0.01 mg/kg Priming Dose): 75-90 sec
      • Priming Dose Accelerates the Onset of Paralysis from the Intubation Dose Which Follows
    • Onset of Intubation-Level Paralysis (When Not Using a 0.01 mg/kg Priming Dose): 180 sec
      • Note that Not Using a Priming Dose Results in a Long Time to Achieve Adequate Intubation Conditions (Potentially Requiring Bag-Valve-Mask Ventilation to Maintain Oxygenation)
    • Duration of Paralysis: 25-30 min
• Clinical Efficacy-Use of Neuromuscular Junction Antagonists for Rapid Sequence Intubation (RSI)
  • In Multicenter, Prospective, Observational Study, Neuromuscular Blocker Administration for Emergent Endotracheal Intubation in the Intensive Care Unit was Associated with Decreased Hypoxemia and Decreased Procedure-Related Complications (Crit Care Med, 2012) [MEDLINE]
  • In Single Center Observational Study, Neuromuscular Junction Antagonist Administration for Emergent Endotracheal Intubation in the Intensive Care Unit was Associated with Increased First-Pass Success Rates (Even with the Use of a Video Laryngoscope), But Did Not Impact Procedure-Related Complication Rates (Ann Am Thorac Soc, 2015) [MEDLINE]
• Clinical Efficacy-Comparison of Neuromuscular Junction Antagonists for Rapid Sequence Intubation (RSI)
  • While Data are Contradictory Regarding the Efficacy of Succinylcholine vs Rocuronium, in Clinical Use, There is Little Difference Between These Two Agents (Except for the Significantly Longer Duration of Paralysis with Rocuronium)
    • Meta-Analysis of Succinylcholine vs Rocuronium for Rapid Sequence Intubation (Acad Emerg Med, 2002) [MEDLINE]: n = 40 studies
      • Succinylcholine Created Excellent Intubation Conditions More Reliably than Rocuronium
      • If a Second-Line Agent was Required, Rocuronium Used with Propofol Created Intubation Conditions Equivalent to Those with Succinylcholine
    • Meta-Analysis of Vecuronium vs Rocuronium for Rapid Sequence Intubation (Clin Exp Pharmacol Physiol, 2006) [MEDLINE]” n = 21 studies
      • The Result of the Meta-Analysis of Differences was -57.9 sec (95% CI: -71.4 to -44.3 sec), Favoring Rocuronium Over Vvecuronium
    • Comparative Study of Succinylcholine vs Rocuronium for Rapid Sequence Intubation (Acad Emerg Med, 2011) [MEDLINE]: n = 327 intubations
      • Succinylcholine and Rocuronium were Equivalent with Regard to First-Attempt Intubation Success in the Emergency Department When Dosed According to the Ranges Used in the Study
    • Systematic Review of Succinylcholine vs Rocuronium for Rapid Sequence Intubation (Cochrane Database Syst Rev, 2015) [MEDLINE]: n = 4,151 (50 trials)
      • Succinylcholine was Superior to Rocuronium for Achieving Excellent Intubating Conditions (Risk Ratio 0.86; 95% CI: 0.81-0.92) and Clinically Acceptable Intubating Conditions (Risk Ratio 0.97; 95% CI: 0.95-0.99)
    • Observational Study of Succinylcholine vs Rocuronium for Rapid Sequence Intubation (Ann Emerg Medl, 2018) [MEDLINE]: n = 2,275 intubations with succinylcholine and 1,800 intubations with rocuronium
      • No Difference Between Paralytic Choice with Regard to First-Pass Rapid Sequence Intubation Success or Peri-Intubation Adverse Events
    • Multicenter, Single-Blind, Noninferiority, Randomized Trial of Succinylcholine vs Rocuronium for Rapid Sequence Intubation (JAMA, 2019) [MEDLINE]: n = 1,248
      • Among Patients Undergoing Endotracheal Intubation in an Out-of-Hospital Emergency Setting, Rocuronium, as Compared with Succinylcholine, Failed to Demonstrate Noninferiority with Regard to First-Attempt Intubation Success Rate
• Society of Critical Care Medicine Clinical Practice Guidelines for Rapid Sequence Intubation in the Critically Ill Adult Patient (2023) (Crit Care Med, 2023) [MEDLINE]
  • In Critically Ill Adults Undergoing Endotracheal Intubation, Administration of a Neuromuscular Junction Antagonist is Recommended When a Sedative-Hypnotic Induction Agent is Used for Intubation (Strong Recommendation, Low Quality of Evidence)
  • Administration of Either Rocuronium or Succinylcholine (When There are No Known Contraindications to Succinylcholine) is Recommended for Rapid Sequence Intubation (Conditional Recommendation, Low Quality of Evidence)

Paralytic Reversal Agents

• Sugammadex (Bridion) (see Sugammadex)
  • Pharmacology: γ-cyclodextrin which binds to vecuronium or rocuronium in a stable 1:1 complex, resulting in encapsulation (chelation) of the drug and consequent decreased availability of free drug to bind to the neuromuscular junction nicotinic acetylcholine receptors
    • Dose (Intravenous): 16 mg/kg (reverses neuromuscular blockade within approximately 3 min)
  • Clinical Utility
    • Sugammadex May Be Considered to Reverse Rocuronium/Vecuronium-Induced Neuromuscular Blockade in a “Can’t Ventilate, Can’t Intubate” Situation

Laryngoscopy Blades

Direct Laryngoscopy Blades

• Macintosh Blade
  • Curved Blade
  • Tip is Inserted into the Vallecula
  • Size: 3 or 4 for adults
• Miller Blade
  • Straight Blade
  • Tip is Inserted on Top of Epiglottis
  • Size: 3 or 4 for adults

Video Laryngoscope (Glidescope, etc)

Technique

• Tip is Inserted into the Vallecula

Clinical Utility

• 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]

Disadvantages

• Failure of Video Laryngoscopy is Typically Related to Inability to Pass the Endotracheal Tube Despite Visualization of the Glottis
  • In Contrast, Failure of Direct Laryngoscopy is Typically Related to Inability to Visualize the Glottis
• Secretions/Blood in the Airway May Obscure the View of the Video Laryngoscope

Clinical Efficacy

• Systematic Review/Meta-Analysis of Video Laryngoscopic vs Direct Laryngoscopic Endotracheal Intubation in the ICU (Intensive Care Med, 2014) [MEDLINE]: 9 trials (n = 2133) comparing direct laryngoscopic vs video laryngoscopic intubation
  • 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
• Secondary Analysis of Predictors of Difficult Video Laryngoscopy with GlideScope or C-MAC® with D-Blade (Br J Anaesth, 2016) [MEDLINE]
  • Characteristics Associated with Greater Risk for Difficult Video Laryngoscopy
    • Head and Neck Position of “Supine Sniffing” vs “Supine Neutral” (Odds Ratio 1.63; 95% CI: 1.1-2.31)
    • Undergoing Otolaryngologic or Cardiac Surgery vs General Surgery (Odds Ratio 1.89; 95% CI: 1.19, 3.01 and Odds Ratio 6.13; 95% CI: 1.85-20.37], respectively)
    • Intubation Performed by an attending anaesthestist vs a supervised resident (Odds Ratio 1.83, 95% CI: 1.14-2.92)
    • Small Mouth (Odds Ratio 1.18; 95% CI: 1.02-1.36)
• Single-Center Observational Study of Video Laryngoscopy and Difficult Airway Characteristics in the ICU (Ann Am Thorac Soc, 2017) [MEDLINE]
  • Presence of Blood in the Airway, Airway Edema, Cervical Immobility, and Obesity are Associated with Higher Odds of First-Attempt Failure with Video 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
• Randomized Trial of Video Laryngoscopy vs Direct Laryngoscopy on Successful First-Pass Orotracheal Intubation in ICU Patients (JAMA, 2017) [MEDLINE]: n = 371
  • In ICU Requiring Intubation, Video Laryngoscopy, as Compared to Direct Laryngoscopy, Did Not Improve First-Pass Orotracheal Intubation Rates
  • In Post-Hoc Analysis, Video Laryngoscopy was Associated with Higher Rates of Severe Life-Threatening Complications, But Not with Mild-Moderate Life-Threatening Complications
  • The Proportion of First-Attempt Intubations Performed by Non-Experts (Primarily Residents, n = 290) Did Not Differ Between the Groups (84.4% with Video Laryngoscopy vs 83.2% with Direct Laryngoscopy; Absolute Difference 1.2% [95% CI, -6.3% to 8.6%]; P = .76)
  • The Median Time to Successful intubation was 3 min (range, 2-4 min) for Both Video Laryngoscopy and Direct Laryngoscopy (Absolute Difference, 0 [95% CI, 0 to 0]; P = .95)
• Rapid Sequence Intubation Has High First-Pass Endotracheal Intubation Success Rate with Video Laryngoscopy (90%) in Patients with Anticipated Difficult Airways (J Emerg Med, 2017) [MEDLINE]
  • Only 11% of Non-Cardiac Arrest Patients Had a Predicted Difficult Airway in this Study and None Required a Surgical Airway
• 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
• Australian/New Zealand Survey Study of Intubation Practices in the Intensive Care Unit (Crit Care Resusc, 2019)[MEDLINE]
  • Propofol was the Preferred Induction Agent (67% of Respondents) and rocuronium was the Preferred Neuromuscular Blocking Agent (58% of Respondents)
  • Video Laryngoscopes were Immediately available in 97% of the ICU’s and were Used as the First-Line Device by 43% of Respondents
• DEVICE Trial of Video Laryngoscopy in Critically Ill Adults in Emergency Department and Intensive Care Unit Settings (NEJM, 2023) [MEDLINE]: n = 1,417
  • Successful First-Attempt Intubation Occurred in 85.1% of Patients in the Video Laryngoscope Group and 70.8% of Patients in the Direct Laryngoscope Group (Absolute Risk Difference of 14.3 Percentage Points; 95% CI: 9.9 to 18.7; P < 0.001)
  • A Total of 21.4% of Patients in the Video Laryngoscope Group and 20.9% of Patients in the Direct Laryngoscope Group Had a Severe Complication During Intubation (Absolute Risk Difference of 0.5 Percentage Points; 95% CI: -3.9 to 4.9)
  • Safety Outcomes (Including Esophageal Intubation, Injury to the Teeth, and Aspiration) were Similar in the Two Groups

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 Stylet (Clarus Video System, Shikani Optical Stylet, Bonfils Retromolar Intubation Fiberscope, Levitan FPS Scope)

• 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)

“Awake” Direct Laryngoscopic Intubation

Definition

• Definition of Awake Intubation: use of topical anesthesia with light sedation (but without the use of a paralytic agent)

Relative Contraindications (J Emerg Med, 2017) [MEDLINE]

• Active Vomiting
• Hypercapnia
• Inability to Protect Airway
• Active Oral Hemorrhage/Hemoptysis/Hematemesis
• Refractory Hypoxemia
• Hemodynamic Instability

Advantages of Awake Endotracheal Intubation

• Maintains the Patient’s Spontaneous Ventilation and Airway Reflexes
  • Avoids the Apneic Period of Rapid Sequence Intubation (with its Attendant Physiologic Consequences)
  • Decreases the Loss of Upper Airway Tone (and Patency)

Disadvantages of Awake Endotracheal Intubation

• May Be Poorly Tolerated by the Patient
• Requires Topical Anesthesia (Which Takes Additional Time to Perform)
• Requires Secretion Control
• Requires Sedation (in Most Cases)
• Longer Time Required to Achieve Intubation

Clinical Efficacy

• Review of Awake Laryngoscopy in the Emergency Department ( J Emerg Med, 2017) [MEDLINE]

Technique

• Bronchoscope (see Bronchoscopy)

Clinical Efficacy

• 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]

Technique

• Disadvantages
  • Higher Incidence of Maxillary Sinusitis