Just a small tip I found interesting. Not life saving, but it might score extra points with the ED and ICU nurses – and help the patient. Nasal prongs can’t deliver much oxygen due to their drying effect on the nasal mucosa. Hudson masks or non-rebreather masks are sometimes not that well tolerated.

We’ve all seen the patient that gets restless and combative with a face mask, or simply wears it on his forehead. HFNC seems a little too much, or you don’t have it. What to do? Sedate the patient? Or put down a nasal pharyngeal catheter for oxygen delivery?

NPO is achieved by insertion of a size 10 gauge oxygen catheter (for adults) passed through the nares and advanced to the depth of the nasopharynx. The depth of insertion is determined by the distance from the ala nasi to the tragus… Oxygen flow rates for NPO are generally provided at 2-6 L/min

The measurement mentioned is a guide. I’ve found placing the catheter at that approx depth, and then further guide the placement by listening for breath sounds through the catheter works well. Breath sounds are good, but if the breath sounds are too strong, you might want to withdraw a centimeter so as not to be too far into the pharynx, close to the larynx, where the catheter can irritate.

In the article, they go on to say that NPO gives equivalent oxygenation to a mask oxygen delivered at higher flows. A study from Anaesthesia and Intensive Care reports NPO’s halved the needed oxygen flow rate. It also helps the patient drink, feed and talk more easily while still getting oxygen therapy. And scores higher in patient comfort.

Nasopharyngeal oxygen (NPO) as a safe and comfortable alternative to face mask oxygen therapy, Aust Crit Care. 2006

This study found NPO’s to be more oxygen effecient than both face masks and nasal prongs to achieve a sat>95%. They also found NPO’s and nasal prongs to be rated higher in patient comfort than face masks. For insertion, you might want to use a gel with lignocain to improve comfort.

Nasopharyngeal oxygen in adult intensive care–lower flows and increased comfort, Anaesth Intensive Care. 2004

The method originated in neonatal and paediatric medicine where it seems to be used in quite a few places. And with its better comfort and oxygenation, it should work well for the adult ED or ICU population too.

This entry was posted in Emergency Medicine, Intensive Care. Bookmark the permalink.


  1. Pingback: THE 1959 FRUMIN STUDY |

  2. Simon says:

    A very interesting article and thanks for the links too

  3. Tom says:

    The oxygen nasal catheter is “old-school” medicine (roughly 1920s to 1960, then fell out of favor). Simple technique. Concerns sometimes stated were catheter migration, uncertain FIO2, Alar irritation, etc.

    Certainly, less annoying in palliative care.

    I found it worked well with auto vs motorcyclist (thrown 40 feet, unconscious, motorcycle another 50 feet away) who we transported with helmet, in situ, with nasal catheter eliminating straps or covering, and avoiding helmet gear. Good outcome.

Leave a Reply

Your email address will not be published. Required fields are marked *