Recurrent high altitude pulmonary edema with blunted chemosensitivity.

A young man who had had two episodes of high-altitude pulmonary edema in the absence of any respiratroy distress was noted to have a depression of his hypoxic and hypercapnic ventilatory drives. It is postulated that because of his blunted ventilaory drives, the patient progessed to coma on exposure to low ambient oxygen tensions (i.e., high altitude) without ever increasing his ventilation. The importance of including highaltitude pulmonary edema in the differential diagnosis of any patient who is admitted with coma after a sojourn at high altitude is stressed.