Discomfort associated with underhumidified high-flow oxygen therapy in critically ill patients

Chanques G, Constantin J-M, Sauter M, Jung B, Sebbane M, Verzilli D, Lefrant J-Y,  Jaber S.

This randomised cross-over study set out to measure the discomfort in non-intubated patients under high-flow oxygen therapy (>5 L/min) humidified with bubble through (BH) or heated humidifiers (HH). In addition the hygrometric properties of oxygen with a BH and an HH were measured. Discomfort, particularly dryness of the mouth and throat, was measured using a 0–10 numerical rating scale (NRS).


The results showed that both mouth and throat dryness were significantly lower with the HH than with the BH. The mean absolute humidity measured at an ambient temperature of 26°C with the HH was two times greater than with the BH regardless of the flow rate.


Intensive Care Medicine 2009; 35: 996-1003


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