Positive airway pressure for high-altitude pulmonary oedema.

Expiratory positive airway pressure was studied on Mount McKinley, Alaska, at an altitude of 4400 m, in three climbers with high-altitude pulmonary oedema and five climbers without evidence of this disorder. In the subjects with high-altitude pulmonary oedema oxygen saturation improved from 53.3 +/- 10.1% to 72.0 +/- 5.7% with expiratory positive airway pressure of 10 cm water. Oxygen saturation, heart rate, and respiratory rate did not change in healthy climbers. No adverse effects were noted. Improved oxygen saturation did not persist when expiratory positive airway pressure was discontinued. This procedure may be useful as a temporary first-aid measure in high-altitude pulmonary oedema.