Oxygen


History of Oxygen Use

Physiology of Oxygen

Indications

Acute Coronary Syndrome (ACS) (see Coronary Artery Disease)

Rationale

Clinical Efficacy

Recommendations (American Heart Association 2015 Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care) (Circulation, 2015)[MEDLINE]

Recommendations (British Medical Journal-Oxygen Therapy for Acutely Ill Medical Patients: Clinical Practice Guideline, 2018) (BMJ, 2018) [MEDLINE]

Air Embolism (see Air Embolism)

Clinical Efficacy

Carboxyhemoglobinemia (see Carboxyhemoglobinemia)

Rationale

Clinical Efficacy

Recommendations (British Medical Journal-Oxygen Therapy for Acutely Ill Medical Patients: Clinical Practice Guideline, 2018) (BMJ, 2018) [MEDLINE]

Cluster Headache (see Cluster Headache)

Clinical Efficacy

Recommendations (British Medical Journal-Oxygen Therapy for Acutely Ill Medical Patients: Clinical Practice Guideline, 2018) (BMJ, 2018) [MEDLINE]

During Rapid Sequence Endotracheal Intubation (RSI) (see Airway Management)

Rationale

Clinical Efficacy

High Altitude in Patients with with Cardiopulmonary Disease (see High Altitude)

General Comments

Hypoxia Altitude Simulation Test (HAST) (see Hypoxia Altitude Simulation Test)

Hypoxia Altitude Simulation Test (HAST) Interpretation

6-Minute Walk Test (6MWT) (see 6-Minute Walk Test)

Clinical Efficacy

Hypoxemia/Hypoxemic Respiratory Failure (see Hypoxemia and Respiratory Failure)

Clinical Conditions

Indications for Long-Term Oxygen Therapy in Chronic Lung Disease (Am J Respir Crit Care Med, 2018) [MEDLINE]

Clinical Efficacy of Oxygen Therapy in Chronic Obstructive Pulmonary Disease (COPD) (see Chronic Obstructive Pulmonary Disease)

Clinical Efficacy of Oxygen Therapy in Interstitial Lung Disease (ILD) (see Interstitial Lung Disease)

Clinical Efficacy of Oxygen Administration in Acute Respiratory Failure (see Respiratory Failure)

Clinical Efficacy of High-Flow Nasal Cannula for Acute Respiratory Failure (see Respiratory Failure)

Clinical Efficacy of High-Flow Nasal Cannula Postextubation

Clinical Efficacy of High-Flow Nasal Cannula in Tracheostomy Patients Who are Weaning (see Tracheostomy)

Clinical Efficacy of High-Flow Nasal Cannula During Bronchoscopy

American College of Physicians Clinical Guideline Recommendations for the Use of High-Flow Nasal Cannula for the Management of Acute Respiratory Failure (Ann Intern Med, 2021) [MEDLINE]

Ischemic Cerebrovascular Accident (CVA) (see Ischemic Cerebrovascular Accident)

Clinical Efficacy

Recommendations (American Heart Association/American Stroke Association Acute Ischemic Stroke Guidelines, 2013) [MEDLINE]

Recommendations (British Medical Journal-Oxygen Therapy for Acutely Ill Medical Patients: Clinical Practice Guideline, 2018) (BMJ, 2018) [MEDLINE]

Methemoglobinemia (see Methemoglobinemia)

Rationale

Clinical Efficacy

Palliative Treatment of Dyspnea (see Dyspnea)

Clinical Efficacy

Pneumothorax (see Pneumothorax)

Rationale

Clinical Efficacy

Recommendations (British Medical Journal-Oxygen Therapy for Acutely Ill Medical Patients: Clinical Practice Guideline, 2018) (BMJ, 2018) [MEDLINE]

Pulmonary Hypertension (see Pulmonary Hypertension)

Clinical Efficacy

Sickle Cell Crisis (see Sickle Cell Disease)

Clinical Efficacy

Recommendations (British Medical Journal-Oxygen Therapy for Acutely Ill Medical Patients: Clinical Practice Guideline, 2018) (BMJ, 2018) [MEDLINE]

Supportive Therapy During General Anesthesia

Rationale

Pharmacology

Background

Administration

Target Peripheral Oxygen Saturation (SpO2) or Arterial Partial Pressure of Oxygen (pO2)

Disorders in Which Lower SpO2 Target is Recommended (British Medical Journal-Oxygen Therapy for Acutely Ill Medical Patients: Clinical Practice Guideline, 2018) (BMJ, 2018) [MEDLINE]

Disorders in Which High SpO2 Target (Approaching SpO2 100%) is Recommended (British Medical Journal-Oxygen Therapy for Acutely Ill Medical Patients: Clinical Practice Guideline, 2018) (BMJ, 2018) [MEDLINE]

Clinical Efficacy-Long-Term Oxygen Therapy

Clinical Efficacy-Oxygen Therapy in Hospitalized Patient

Recommendations (British Thoracic Society Emergency Oxygen Guidelines, 2017) (Thorax, 2017) [MEDLINE]

Recommendations (British Medical Journal-Oxygen Therapy for Acutely Ill Medical Patients: Clinical Practice Guideline, 2018) (BMJ, 2018) [MEDLINE]

Medicare Reimbursement for Oxygen Therapy

General Types of Oxygen Systems

  • Oxygen Concentrator: for home use
  • Lightweight Compressed Gas Cylinder: portable
  • Liquid Oxygen System: portable
  • Portable Oxygen Concentrator (POC): portable device (this is the only device which is currently approved for air travel)
    • Devices: Eclipse, EverGo, FreeStyle, Inogen, XPO2
    • Range of Battery Life 2.5-8 hrs
    • Battery Power is Required for Oxygen Production

Nasal Cannula (NC)

Technique

  • Oxygen is Supplied Via Soft Prongs in Anterior Nares
  • Humidification Via Bubbling Through Saline is Standard Utilized, as Flows >2 L/min Can Be Irritating to the Nasal Mucosa

Range of Oxygen Delivery

  • Range: 25-40% FIO2 (at flow rate 1-6 L/min)
    • As a General Rule, Each Increase in Flow Rate of 1 L/min Accounts for an Approximate 4% Increase in FIO2
      • However, the Actual FiO2 Delivered is Affected by Respiratory Rate, Tidal Volume, Oxygen Flow Rate, and the Amount of Mouth Breathing by the Patient (Thorax, 1992) [MEDLINE]
      • Higher Respiratory Rate Results in Higher Amount of Air Entrainment and Therefore, Decreased FIO2
    • In General, the Most Effective Oxygen Delivery Via Nasal Cannula Occurs During the First 200 msec of the Inspiration

Considerations

  • Nasal Cannula is Generally Better Tolerated than an Oxygen Mask in a Delirious Patient (Due to Claustrophobia, etc)
  • Nasal Cannulas are Inexpensive, Space-Efficient, Transportable, and Easy to Use
  • However, Due to Entrainment and Other Factors, Nasal Cannulas are Very Inefficient
    • Only a Small Percentage of the Oxygen Being Delivered Through the Nasal Cannula Actually Reaches the Alveoli

High-Flow Nasal Cannula (HFNC)

Physiologic Effects and Clinical Benefits

  • Decreases Inspiratory Effort
    • Inspiratory Flow Rates Linearly Decrease the Inspiratory Effort, Improve Lung Aeration, Improve Dynamic Compliance, and Improve Oxygenation (Intensive Care Med, 2017) [MEDLINE]
      • Notably, Most of the Effects on Inspiratory Workload and Carbon Dioxide Clearance were Achieved at the Lowest Flow Rates (Intensive Care Med, 2017) [MEDLINE]
  • Flushes the Posterior Pharynx, Resulting in Decreased Nasopharyngeal Dead Space (NEJM, 2015) [MEDLINE]
    • Improves Efficiency of Ventilation and Oxygen Delivery
  • Generates Turbulent Posterior Pharyngeal Airflow, Facilitating Better Gas Mixing
  • Improves Lung Compliance
    • Italian Prospective, Randomized Crossover Trial of High-Flow Nasal Cannula in Acute Hypoxemic Respiratory Failure (Am J Respir Crit Care Med, 2017) [MEDLINE]
      • High-Flow Nasal Cannula Decreased Inspiratory Effort, Improved Lung Volumes, and Improved Lung Compliance
  • Improves Patient Comfort, as Compared to Oxygen Delivered Via Low-Flow Nasal Cannula or Face Mask (Respir Care, 2010) [MEDLINE] (J Crit Care, 2010) [MEDLINE] (Respir Care, 2014) [MEDLINE]
  • Improves Tolerance in the Delirious Patient, as Compared to an Oxygen Mask or Noninvasive Positive-Pressure Ventilation
  • Increases Tidal Volume (with Decreased Respiratory Rate) (Br J Anaesth, 2011) [MEDLINE] (Respir Care, 2013) [MEDLINE]
  • Induces of a Small Amount of Positive End-Expiratory Pressure (PEEP)
    • Amount of PEEP Achieved is Dose-Dependently Related to the Flow Rate (Respir Care, 2013) [MEDLINE]
      • For Every 10 L/min Increase in the Flow Rate, there is a 0.7 cm H2O Increase in Airway Pressure (with the Mouth Closed) and 0.35 cm H20 Increase (with the Mouth Open) (Respir Care, 2011) [MEDLINE]
      • With Open Mouth Breathing, Lower Levels of PEEP are Generally Observed
    • Physiologic Consequences of the PEEP Effect
      • Decreased Auto-PEEP (If Present)
      • Decreased Work of Breathing: however, high-flow nasal cannula does not decrease the work of breathing as effectively as noninvasive positive-pressure ventilation (or invasive mechanical ventilation)
      • Enhanced Oxygenation in the Setting of Alveolar Filling Processes (Pulmonary Edema, ARDS, etc)
  • Minimizes Entrainment of Room Air (Due to High Flow Rates)
    • Increases the Ability to Deliver a Higher FIO2
    • Results in a More Accurate FIO2, as Compared to Other Delivery Systems
    • This is Clinically Important, Since Patients in Respiratory Distress Can Generate Flow Rates Which Exceed Those Supplied by Many Conventional Oxygen Delivery Systems, Resulting in Entrainment of Room Air (and a Decreased FIO2)
      • However, Open-Mouth Breathing Will Allow Entrainment of Room Air and Obviate this Advantage to Some Extent
  • Warms/Humidifies Secretions
    • Warming and Humidifying Oxygen is More Effective at High Flow Rates (>40 L/min) than at Low Flow Rates: therefore, high-flow nasal cannula systems are better at warming and humidifying than Venturi masks and non-rebreather masks (which use flow rates of 10-15 L/min) or low-flow rate delivery systems (which use flow rates <10 L/min)
    • Increased Mucous Membrane Hydration Facilitates Secretion Clearance, Decreases Work of Breathing, and Decreases Mucous Membrane Dessication/Epithelial Injury

Technique

  • Proprietary Devices
    • Comfort Flo
    • Optiflow
    • Vapotherm
  • Parameters to Set
    • Flow Rate: while high-flow nasal cannula may utilize flow rates of 5-60 L/min, the flow rate is usually initially set at 20-35 L/min
      • May Increase the Flow Rate in Increments of 5-10 L/min, as Required to Improve Oxygenation: this is usually performed to prioritize a decrease in FIO2 to ≤50%
    • FIO2: set between 21%-100% to achieve desired SaO2
      • May Increase (After Flow Rate is Maximized), as Required to Improve Oxygenation
  • Heated, Humidified Circuit
  • Delivery of Nebulized Medications (Albuterol, etc): usually performed using an oral delivery device (as opposed to via the high-flow nasal cannula device)
    • The Efficiency of Delivery of Nebulized Medications Has Not Been Well-Studied with High-Flow Nasal Cannula Systems
  • Duration of Use: may be used for prolonged period of time (multiple days)
  • Transition Back to a Conventional Delivery Oxygen Delivery System: this can usually be achieved when the flow rate is ≤20 L/min and the FIO2 ≤50%

Indications

Contraindications

  • Type II-Hypoxemic, Hypercapnic Respiratory Failure (see Respiratory Failure)
    • Due to Concerns Related to the Worsening of Hypercapnia
    • High-Flow Oxygen Administered to Patients with Chronic Obstructive Pulmonary Disease in the Pre-Hospital Setting Has Been Demonstrated to Worsen Hypercapnia (BMJ, 2010) [MEDLINE]: caution should be exercise when high-flow oxygen is used in this patient population
  • Mid-Maxillary Facial Trauma or Upper Airway Surgery
    • Due to Concern with Regard to High Pressure Precipitating Air Embolism
  • Suspected Pneumothorax (see Pneumothorax)
    • Due to Concerns Related to the Development of Barotrauma

Adverse Effects/Complications

  • Barotrauma: although the risk of barotrauma with high-flow nasal cannula is lower than that with noninvasive positive-pressure ventilation or intubation with invasive mechanical ventilation
  • Gastric Distention (with Predisposition to Aspiration)

Venturi Mask (Ventimask)

Technique

  • Simple Mask Which Fits Loosely Over the Nose and Mouth
  • Plastic Mask Serves as an Oxygen Reservoir
  • Exhaled Gas Escapes Through Exhalation Ports on the Mask: however, these exhalation ports also allow entrainment of room air into the mask (decreasing the effective FIO2)
    • For This Reason, the Exact FIO2 Cannot Be Precisely Determined in an Individual Patient
  • Flow Rate of >5 L/min is Recommended to Prevent Carbon Dioxide Rebreathing (Acta Anaesthesiol Scand, 1991) [MEDLINE]

Range of Oxygen Delivery

  • Range: 35-50% FIO2 (at 6-10 L/min)
    • The Actual FIO2 Delivered is Affected by the Patient’s Respiratory Rate and the Mask Fit

Considerations

  • Percent Oxygen is Affected by Mask Fit and Patient’s Respiratory Rate

Partial Rebreather Mask

Technique

  • Consists of a Simple Mask with an Attached Oxygen Reservoir
  • Inspiratory Flow Comes Predominantly from the Oxygen Inflow from the Source and the Oxygen Reservoir
    • While Entrainment of Room Air Via the Exhalation Ports is Usually Minimal (with Less Entrainment than a Simple Mask/Venturi Mask), the Exact FIO2 Still Cannot Be Precisely Determined in an Individual Patient
  • Oxygen Flow Rate Must Be Adjusted to Keep the Reservoir from Collapsing, to Maintain a High Oxygen Percentage in the Reservoir

Range of Oxygen Delivery

  • Range: 50-60% FIO2 (at flow rates 10-12 L/mi)

Considerations

  • May Be Useful During Patient Transport, When Conservation of Oxygen is Important

Non-Rebreather (NRB) Mask

Technique

  • Oxygen Mask and Reservoir System Which Contains Two Valves Which Limit the Mixing of Exhaled Gases and Room Air with the Oxygen Supply
    • Only One of the Two Exhalation Ports Has a One-Way Valve
      • This Safety Feature Allows the Patient to Still Obtain Room Air Through the Open Port, if the Oxygen Flow to the Mask is Interrupted for Some Reason
    • The Second One-Way Valve is Located Between the Reservoir and the Mask and it Functions to Prevent the Flow of Exhaled Gas into the Reservoir
  • Oxygen Flow Rate Must Be Adjusted to Keep the Reservoir from Collapsing, to Maintain a High Oxygen Percentage in the Reservoir

Range of Oxygen Delivery

  • Range: 65-95% FIO2 (at flow rates 10-15 L/min with a good mask seal)
    • Non-Rebreather Mask Reliably Provides the Highest FIO2 of All Devices to a Spontaneously Breathing Patient

Considerations

  • Adequate Mask Fit is Required to Achieve High FIO2

Blow By

Indications

  • Spontaneously-Breathing Child with Low FIO2 Requirement and Who Cannot Tolerate an Oxygen Mask
    • Particularly for Conditions Such as Croup, Bronchiolitis, Bronchospasm, etc

Technique

  • Blow By Utilized Oxygen Tubing, Corrugated Plastic Tubing, etc Held a Short Distance from the Child’s Face

Range of Oxygen Delivery

  • Range: <30% FIO2
    • In General, Blow By is a Less Reliable Means of Oxygen Delivery

Oxygen Hood

Technique

  • Oxygen Hood is a Clear Plastic Cylinder Which Encloses the Patient’s Head
  • Oxygen Hoods are Used Predominantly in Infants/Children
  • Hood Systems Provide Temperature and Humidification Control
  • Exhaled Gas Escapes Via the Opening at the Neck

Range of Oxygen Delivery

  • Range: 30-90% FIO2

Considerations

  • Noisy

Oxygen Tent

Technique

  • Oxygen Tent is a Clear Plastic Shell Which Encloses the Head and Upper Body
  • Oxygen Tents are Used Predominantly in Infants/Children
  • Tent Systems Provide Temperature and Humidification Control

Range of Oxygen Delivery

  • Range: 25-50% FIO2

Considerations

  • Noisy
  • Mist within the Tent (Due to Humidification) May Obscure View of the Patient: which obviously may be problematic with regard to patient monitoring
  • Allows Only Limited Access to the Patient

Oxygen-Conservation Devices

Indications

  • Oxygen Delivery and Conservation for an Ambulatory Patient

Types of Oxygen-Conservation Systems

  • Demand Pulse System
    • Principle: using a flow sensor, these devices deliver a metered dose of oxygen during the earliest part of each inspiration (during the first 0.5 sec), when it can maximize gas exchange
    • Systems: Chad-Oxymatic, Devilbiss-PD-1000, Helios, Invacare-Venture, Nellcor PB-CR50, Respironics e-POD, EasyPulse, Bonsai, Sage, Evolution, Evolution Motion, Impulse
    • Disadvantages
      • Audible Pulse Noise
      • Potential for Device Failure: rare
  • Reservoir Cannulas
    • Principle: storage of oxygen in a reservoir during expiration (oxygen is available as a bolus during the next inspiration)
    • Efficiency: reservoir nasal cannula is approximately 2-4 fold as efficient as continuous flow delivery via a nasal cannula (for example: oxygen supplied at 0.5 L/min via a reservoir cannula is equivalent to 2 L/min via a continuous flow nasal cannula)
    • Systems
      • Fluidic Reservoir Cannula: uses a “mustache” reservoir to function as both an oxygen-conserving and high-flow device (at 1-16 L/min)
      • Oxymizer: uses a “mustache” oxygen reservoir which is located below the nose
      • Oxymizer Pendant: uses an oxygen reservoir which is located on the anterior chest
    • Clinical Utility: while reservoir systems can be used to decrease the flow rate in a patient on low-flow oxygen therapy, they are more commonly used to provide a higher oxygen concentrations to a patients who requires a flow rate of ≥4 L/min
  • Transtracheal Oxygen Catheter
    • Principle: cannula inserted into the trachea via a skin incision in the neck (bypassing the dead space of the upper airway)
    • Efficiency: transtracheal catheter is approximately 2-3 fold more efficient than continuous flow delivery via a nasal cannula (this increases to 7-fold increase when using a demand pulse system with the transtracheal catheter)
    • Advantages
      • Decreased Dead Space: oxygen enters the trachea directly
      • Decreased Total Inspired Minute Ventilation: flow from catheter allows less gas inspiration via the mouth, resulting in a decreased work of breathing
      • Ensured Delivery of Oxygen
      • Increased Carbon Dioxide Elimination Efficiency: therefore, despite decreased total inspiratory minute ventilation, pCO2 remains unchanged
        • Oxygen Flow from the Catheter Flushes the Airways Proximal to the Catheter Tip During Expiration, Decreasing the Amount of Carbon Dioxide Which Returns to the Alveoli During the Next Inspiration
        • Oxygen Flow from the Catheter Generates Turbulent Flow in the Airway, Facilitating Gas Mixing Distal to the Catheter Tip and Increasing Carbon Dioxide Washout
    • Disadvantages
      • Invasive (Requires Surgical Placement of a Transtracheal Catheter)
    • Clinical Utility: may be used in a patient with refractory hypoxemia (similar to reservoir cannula systems)

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

  • Range: 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

  • Range: 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]

Noninvasive Positive-Pressure Ventilation (NIPPV) (see Noninvasive Positive-Pressure Ventilation)

Range of Oxygen Delivery

  • Range: 21%-100% FIO2

Considerations

  • Appropriate Patient Selection is Critical, with the Following Patient Groups Having the Most Comprehensive Data in the Literature Demonstrating Clinical Benefit with the Use of NIPPV

Mechanical Ventilation (see Mechanical Ventilation-General)

Range of Oxygen Delivery

  • Range: 21%-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)

Adverse Effects/Complications

Pulmonary Adverse Effects/Complications

Absorptive Atelectasis (see Atelectasis)

  • Physiology
    • High FIO2 Causes a Washout of Alveolar Nitrogen and Replacement by Oxygen, Resulting in Absorption of Alveolar Oxygen into the Blood
      • End Result is a Small Alveolus Which is Predisposed to Collapse (i.e. Atelectasis)
    • Inhalation of 100% Oxygen for Only 5 min During Anesthesia Has Been Demonstrated to Induce Atelectasis (Anesthesiology, 2003) [MEDLINE]
    • Risk Factors for Alveolar Collapse (Atelectasis) in this Setting
      • High Metabolic Demand with an Increased Rate of Oxygen Uptake
      • Low Regional V/Q Ratio: due to low ventilation to the region, oxygen diffuses from the alveolus into the capillary faster than it is replenished by inhaled oxygen
      • Surfactant Abnormalities: such abnormalities predispose the alveolus to collapse (and further decrease the regional V/Q ratio)
      • Ventilation at Low Tidal Volumes (or with Low PEEP): these factors predispose to alveolar collapse
  • Clinical Consequences of Absorptive Atelectasis
    • Decreased Vital Capacity
      • Decreased Vital Capacity (Up to 20% Has Been Demonstrated In Studies (New Horiz, 1993) [MEDLINE] (Curr Opin Pulm Med, 1998) [MEDLINE]: likely due to both absorptive atelectasis and shallow breathing due to the pain of pleural irritation associated with hyperoxia
    • Worsened Hypoxemia with Intrapulmonary Shunt
      • On 100% FIO2, Shunt is Usually Absent in Younger Patients, But May Occur in Older Patients (Shunt May Be as High as 11% in Older Patients) (J Clin Invest, 1974) [MEDLINE]
      • Once Absorptive Atelectasis Occurs, it is Not Readily Reversible by a Decrease in FIO2 (Am J Respir Crit Care Med, 2000) [MEDLINE]: this demonstrates the importance of rapid down-titration of the FIO2 as soon as possible

Aerosol Generation with Potential Spread of Infection (SARS-CoV-2, etc)

  • Epidemiology
    • Small Study of Aerosol Generation in 10 Normal Subjects with Various Oxygen Delivery Methods (Non-Humidified Nasal Cannula, Face Mask, Heated and Humidified High-Flow Nasal Cannula, and Noninvasive Positive-Pressure Ventilation) (Am J Respir Crit Care Med, 2020) [MEDLINE]
      • Measured in a Negative Pressure Room, Oxygen Delivery Via Humidified High-Flow Nasal Cannula and Noninvasive Positive-Pressure Ventilation Did Not Increase Aerosol Generation from the Respiratory Tract in Healthy Humans with No Active Pulmonary Disease

Airway Injury

  • Physiology
    • Concentration of Reactive Oxygen Intermediates In Exhaled Gas Increases After Only 1 hr of Breathing 28% FIO2, Regardless of the Presence of Lung Disease (Thorax, 2004) [MEDLINE]
    • Erythema/Edema of Large Airways (Due to Hyperoxia Bronchitis) is Bronchoscopically Observed in Patients Treated with 90% FIO2 for 6 hrs (Ann Intern Med, 1975) [MEDLINE]
    • Volunteer Studies Breathing FIO2 100% x 6-48 hrs Variably Induced Tracheobronchitis, Substernal Burning, Chest Tightness, and a Dry Cough
  • Clinical

Induction of Ignition of Other Flammable Materials in the Presence of Open Flame, Heat Source, or Electrical Device

  • Epidemiology
    • Facial Hair and the Use of Hair Products Containing Oils/Alcohols are a Risk Factor for Combustion (Mayo Clin Proc, 2014) [MEDLINE]
    • Safety of Electronic Cigarettes with Oxygen Therapy is Unclear
    • May Occur During Surgical Airway Procedures Using Sources of Ignition (Laser, etc)
  • Physiology
    • Oxygen Itself is Not Flammable, But it Induces Other Materials to Catch Fire at Lower Temperatures and to Burn with a Hotter Flame
  • Prevention
    • Avoidance of Smoking
    • Supplemental Oxygen Should Not Be Used within 5 Feet of an Open Flame, Heat Source, or Electrical Device
  • Clinical
    • Facial/Upper Airway Burns

Parenchymal Oxygen Toxicity

  • Epidemiology
    • Prior Exposure to Bleomycin Increases the Risk of Toxicity from Hyperoxia (Am Rev Respir Dis. 1984) [MEDLINE] (see Bleomycin)
  • Physiology
    • Mechanisms by Which Hyperoxia Contributes to the Development of Lung Injury
      • Absorptive Atelectasis: as described above
      • Formation of Reactive Oxygen Intermediates (Such as Superoxide Anion, Hydroxyl Radical, and Hydrogen Peroxide) Which Overwhelm the Cell’s Antioxidant Defense Mechanisms
        • Concentration of Reactive Oxygen Intermediates In Exhaled Gas Increases After Only 1 hr of Breathing 28% FIO2, Regardless of the Presence of Lung Disease (Thorax, 2004) [MEDLINE]
        • Reactive Oxygen Intermediates React with Various Intracellular Macromolecules (Impairing Their Function), Resulting in Cell Death
      • Impairment of Bactericidal Function of Immune Cells, Resulting in an Increased Risk of Infection
      • Impairment of Mucociliary Clearance, Resulting in an Increased Risk of Infection
      • Increased Susceptibility to Mucous Plugging
      • Induction of a Deleterious Inflammatory Response, Resulting in Secondary Apoptosis and Tissue Damage
    • Volunteer Studies Breathing FIO2 100% x 6-48 hrs Variably Induced Tracheobronchitis, Substernal Burning, Chest Tightness, and a Dry Cough
    • Tolerance of Hyperoxia Appears to Be Related to an Ability to Generate Antioxidants: this tolerance may be genetically determined
    • Phases of Oxygen Toxicity (Phases Overlap)
      • Acute/Exudative Phase: usually begins within 48-72 hrs, depending on inspired oxygen fraction (and is believed to be reversible)
        • Perivascular, Interstitial, and Alveolar Edema -> atelectasis and alveolar hemorrhage
      • Subacute/Proliferative Phase: usually begins after 4th-7th day (and is believed to be irreversible)
        • Rebsorption of Exudates
        • Hyperplasia of Type II Pneumocytes
        • Deposition of Collagen and Elastin in Interstitium and Hyaline Membrane Deposition
  • Clinical
  • Treatment
    • Preventive Measures: maintain pO2 <80 mmHg and FIO2 <40-50%

Worsening of Hypercapnia in Hypercapnic Patient (see Chronic Obstructive Pulmonary Disease)

  • Epidemiology
    • High-Flow Oxygen Administered in Chronic Obstructive Pulmonary Disease Patients (in the Pre-Hospital Setting) Has Been Demonstrated to Worsen Hypercapnia (BMJ, 2010) [MEDLINE]
    • Supplemental Oxygen Therapy Can Worsen Hypercapnia in Patients with Neuromuscular Disease with Chronic Hypercapnia (Mayo Clin Proc, 1995) [MEDLINE]
  • Physiology
    • Patients with Chronic Hypercapnia Have a Limited Ability to Increase Their Alveolar Ventilation
    • Mechanisms
      • Anxiolytic/Anti-Dyspneic Effects of Supplemental Oxygen Promotes Sleep (Particularly in Patients Who are Sleep-Deprived from Respiratory Failure), Resulting in a Sleep-Related Decrease in Respiratory Drive
      • Hyperoxia (Acting Via Peripheral Chemoreceptors) Modestly Blunts the Hypoxic Ventilatory Drive ( (Lancet, 1977) [MEDLINE]
      • Hyperoxia Causes Oxygen-Induced Bronchodilation of Poorly-Perfused Lung Units, Worsening V/Q Mismatch and Increasing Physiologic Dead Space (i.e. Wasted Ventilation)
      • Haldane Effect
        • Hyperoxia Increases Oxyhemoglobin
        • Oxyhemoglobin Binds Carbon Dioxide Less Avidly than Deoxyhemoglobin, Resulting in Carbon Dioxide Dissociation from Hemoglobin and Increase in Blood Carbon Dioxide Levels
      • Hyperoxia-Associated Hypoventilation Decreases Inspiratory Flow Demand (Decreasing Respiratory Rate/Volume), Resulting in Decreased Entrainment of Room Air Around a Face Mask/Nasal Cannula: this effectively increases the FIO2 (even if the flow rate of the supplemental oxygen remains unchanged) further enhancing the effects of supplemental oxygen via the above mechanisms (Lancet, 2001) [MEDLINE]

Other Adverse Effects/Complications

Claustrophobia (see Claustrophobia)

  • Epidemiology
    • May Especially Occur with the Use of Face Mask Supplemental Oxygen

Impaired Patient Communication

  • Epidemiology
    • May Especially occur with the use of Face Mask Supplemental Oxygen

Impaired Patient Mobility

  • Clinical
    • May Result in Trips/Falls

Oxygen Cylinder Falling Over Resulting in Dislodgment of the Regulator and Propulsion

  • Epidemiology
    • Oxygen Cylinder May Become Propelled Like a Missile (Anesthesiology, 1978) [MEDLINE]
      • For This Reason, Oxygen Cylinders Should Be Properly Secured to Avoid Them Falling Over

Retinopathy of Prematurity (Retrolental Fibroplasia)

  • Epidemiology
    • Occurs in Infants

References

General

History

Current Use of Oxygen in Clinical Practice

Physiology of Oxygen

Indications

Acute Coronary Syndrome (see Coronary Artery Disease)

Air Embolism (see Air Embolism)

Carboxyhemoglobinemia (see Carboxyhemoglobinemia)

Chronic Obstructive Pulmonary Disease (COPD) (see Chronic Obstructive Pulmonary Disease)

During Rapid Sequence Endotracheal Intubation (see Endotracheal Intubation and Airway Management)

High Altitude (see High Altitude)

Hypoxemia/Hypoxemic Respiratory Failure (see Hypoxemia and Respiratory Failure)

Ischemic Cerebrovascular Accident (CVA) (see Ischemic Cerebrovascular Accident)

Other Lung Diseases

Palliative Treatment of Dyspnea (see Dyspnea)

Pulmonary Hypertension (see Pulmonary Hypertension)

Administration

Oxygen Delivery Systems

High-Flow Nasal Cannula

Transtracheal Oxygen

Adverse Effects/Complications