Nasopharyngeal oxygen therapy, the delivery of supplementary oxygen into the nasopharynx via a fine catheter placed through the nose, is a simple technique used in postoperative anaesthetic care units and paediatric intensive care, but never described in the setting of adult intensive care. In a prospective crossover design, we compared nasopharyngeal oxygen therapy with semi-rigid plastic mask (Hudson Mask) in 50 unintubated adult patients receiving supplemental oxygen. We measured oxygen flow rate to achieve cutaneous saturations 93 to 96%, and patient comfort by visual analogue score. Nasopharyngeal oxygen therapy consumed significantly less oxygen than mask administration (3.0+/-0.9 vs 67+/-2.1 l/min, P<0.001) and was associated with significantly higher comfort than the mask (7.5+/-1.6 cm vs 5.2+/-1.8, P<0.001).
