Apneic oxygenation

Overview

Apneic oxygenation is a technique that prolongs "safe apnea time" (time until desaturation to SaO2=88-90%) after induction of apnea. This increases time for laryngoscopy/intubation.

• an adjunct to preoxygenation: used to prolong oxygenation after optimal preoxygenation
• low cost in terms of resources and set-up

Physiology

• gas exchange during apnea creates subatmopsheric pressure in the alveoli
  • in healthy lungs, 200-250mL O2 per minute can be drawn into blood stream
  • in the absence of ventilation (i.e. during apnea), only 10-20mL CO2 enters alveoli from bloodstream per minute, due to increased CO2 tension
  • this causes a net decrease in gas in the alveoli
• this gradient can draw air into the lungs, even absent diaphragmatic movement
• increases safe apnea time in healthy volunteers from 1 minute (room air) to 8-9 minutes

Indications

• intubation

Contraindications

• severe maxillofacial trauma
• obstructed nares

Equipment Needed

• nasal cannula
• second oxygen source, e.g. mobile O2 tank

Procedure

1. Start pre-oxygenation while sitting upright, only lay back once RSI drugs pushed.
2. During preoxygenation, keep the nasal cannula on underneath your primary preoxygenation technique.
   • This can be achieved whether you use a mask, NPPV, or BVM; a good seal can still be obtained. Alternatively, you can use the high flow nasal cannula technique for preoxygenation.
   • Normal adjunctive airway techniques/equipment (jaw thrust, oropharyngeal airway) remain useful. In particular, nasal trumpet can maintain patencny of at least one nare.
3. Attach the nasal cannula to a separate oxygen source at 15L.
4. After preoxygenation, leave the nasal cannula on after removing mask/NPPV/BVM. It should not get in the way of laryngoscopy.
   • Consider taping cannula to face to prevent dislodgement.

Complications/Limitations

• complications are limited and most can be quickly remedied by removing nasal cannula
  • if not well-positioned/attached, may complicate laryngoscopy
  • high flow oxygen from nasal cannula is cold and dry; may not be well-tolerated by patient
  • extremely high flow oxygen (>70 L/M) may cause barotrauma
  • increased apnea time increases respiratory acidosis
• not shown to improve saturation in critically ill patients

See Also

Airway Pages

• Pre-intubation
  • Predicting the difficult airway
  • Bag valve mask ventilation
    • Oropharyngeal airway
    • Supraglottic airway
  • Apneic oxygenation
    • EBQ:ED Preoxygenation
• Induction
  • Critical care quick reference
  • Rapid sequence intubation
  • Delayed sequence intubation
• Intubation
  • Intubation (peds)
  • Direct laryngoscopy
  • Video Laryngoscopy
  • Bougie
  • The difficult airway
  • Advanced airway adjuncts
    • Supraglottic airway
  • Non-traditional intubation
    • Awake intubation
    • Nasal intubation
    • Blind digital intubation
• Surgical airways
  • Surgical cricothyrotomy
  • Needle cricothyrotomy
  • Pediatric jet ventilation
• Post-intubation
  • Mechanical ventilation (main)
  • Deterioration after intubation (DOPE)

External Links

https://emcrit.org/pulmcrit/preoxygenation-apneic-oxygenation-using-a-nasal-cannula/

References

• Moran C, Karalapillai D, Darvall J, Nanuan A. Is it time for apnoeic oxygenation during endotracheal intubation in critically ill patients? Critical care and resuscitation. 16(3):233-5. 2014.
• Semler MW, Janz DR, Lentz RJ. Randomized Trial of Apneic Oxygenation during Endotracheal Intubation of the Critically Ill. American journal of respiratory and critical care medicine. 2015.
• Hayes-Bradley C, Lewis A, Burns B, Miller M. Efficacy of Nasal Cannula Oxygen as a Preoxygenation Adjunct in Emergency Airway Management. Annals of emergency medicine. 68(2):174-80. 2016.
• Lynn E. Teller, M.D., Christian M. Alexander, M.D., M. Jack Frumin, M.D., Jeffrey B. Gross, M.D.; Pharyngeal Insufflation of Oxygen Prevents Arterial Desaturation during Apnea. Anesthes 1988;69(6):980-982.