Trick of the Trade: Nasopharyngeal Oxygenation

A 76-year-old obese male with a history of severe COPD presents to your emergency department (ED) in acute respiratory distress. The patient’s large beard prevents an adequate seal with the NIV (non-invasive ventilation) mask, and the patient continues to desaturate. You are fairly sure that this patient will be a difficult airway and optimizing oxygenation prior to and during your intubation attempt would be ideal. Now what?

Trick of the Trade: Nasopharyngeal Oxygenation

Use a nasopharyngeal airway (NPA) to generate positive pressure oxygenation

Traditional nasopharyngeal oxygenation (NPO) uses a thin nasal tube which delivers low flow oxygen directly into the nasopharynx. This technique has been used in critical care, operating room, and pediatric settings but has not yet become common-place amongst ED practitioners [1-6]. Our technique uses the principle of direct NPO with high flow oxygen and allows for the delivery of positive pressure in an easy and practical manner.

Equipment needed

Technique

1. A standard NPA is placed through either nostril.
2. One end of standard wall suction tubing is connected via the included adapter to the NPA while the other end is directly connected to a standard oxygen source.

3. The oxygen source can then be turned up well beyond its regulated range (0-15 L/min) to deliver > 25 L/min of positive pressure oxygen directly into the posterior pharynx. Given that this uses a standard NPA, it also does not obstruct visualization during traditional laryngeal intubation. There is also an automatic safety release in case of excess positive pressure via either the opposite nare or the patient’s open mouth.

Patient Selection

Our technique may be applicable for those who are poor candidates for other traditional oxygenation methods. Examples:

• Classic apneic oxygenation using a standard nasal cannula is an excellent adjunct [7] but may be inadequate in patients with excessive pharyngeal or soft palate tissue that can obstruct airflow.
• NIV using a face mask can be hindered by poor mask seal due to either patient compliance, facial hair or facial deformities, and cannot be used during traditional intubation.
• A LMA may not seat adequate secondary to anatomical trauma, deformities, or other variances.

To our knowledge, this is the only other method that we are aware of that permits positive pressure oxygenation without obstructing direct real-time visualization of the airway.

Caution

While very effective, positive pressure NPO also carries serious risks– mainly aspiration and gastric insufflation. For this reason, we recommend this technique only in patients who cannot be oxygenated using standard methods. This simple and effective trick has been life saving in various clinical scenarios, including angioedema, anaphylaxis, end-stage COPD, severe pneumonia, and trauma patients with anterior-pharyngeal/oral injuries.

What are your thoughts on this trick of the trade?

Trick co-authored by:

Benjamin Wiederhold, MD
Chair, Department of Emergency Medicine, St Joseph Medical Center
Medical Director, Emergency Department, St Joseph Medical Center
Director Emergency Medicine Trauma Services, San Joaquin General Hospital

Reference

1. Zestos MM, Daaboul D, Ahmed Z, Durgham N, Kaddoum R. A novel rescue technique for difficult intubation and difficult ventilation. J Vis Exp. 2011 Jan 17;(47).
2. Boyce JR. Poor man’s LMA: achieving adequate ventilation with a poor mask seal. Can J Anaesth. 2001 May;48(5):483-5.
3. Engström J, Hedenstierna G, Larsson A. Pharyngeal oxygen administration increases the time to serious desaturation at intubation in acute lung injury: an experimental study. Crit Care. 2010;14(3):R93.
4. Baraka AS, Taha SK, Siddik-Sayyid SM, Kanazi GE, El-Khatib MF, Dagher CM, Chehade JM, Abdallah FW, Hajj RE. Supplementation of pre-oxygenation in morbidly obese patients using nasopharyngeal oxygen insufflation. Anaesthesia. 2007 Aug;62(8):769-73.
5. Eastwood GM, Dennis MJ. Nasopharyngeal oxygen (NPO) as a safe and comfortable alternative to face mask oxygen therapy. Aust Crit Care. 2006 Feb;19(1):22-4.
6. Frey B, Shann F. Oxygen administration in infants. Arch Dis Child Fetal Neonatal Ed. 2003 Mar;88(2):F84-8.
7. Weingart SD, Levitan RM. Preoxygenation and prevention of desaturation during emergency airway management. Ann Emerg Med. 2012 Mar;59(3):165-75.e1.

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