[Altitude edema in the Swiss Alps. Observations on the incidence and clinical course in 50 patients 1980-1984].

In the Swiss Alps 50 patients with high altitude edema (high altitude pulmonary edema and/or high altitude cerebral edema) had to be rescued by helicopter during the period 1980-1984. The development, clinical picture and clinical course have been analyzed retrospectively. The patients were 49 men and one woman, generally in good health and well trained. They had ascended from the low-lands to an altitude above 2500 m and subsequently climbed higher. The climbers developed symptoms of acute mountain sickness on the second to third day of high altitude exposure and had to be evacuated by air on the fourth to fifth day. 70% of the cases occurred in the Valais Alps and the rest in the region of the Bernese Alps and the Bernina. The highest incidence of high altitude edema was observed in the Capanna Margherita (4559 m), where one of 588 climbers who stayed overnight had to be air-rescued. This ratio was about one in 4000 mountaineers at the Finsteraarhorn hut (3050 m) and the Monte Rosa hut (2795 m). Evacuation by air was the most successful therapeutic measure and resulted in immediate amelioration of clinical symptoms in 16 patients. 34 climbers had to be admitted to local hospitals due to severe high altitude pulmonary and/or cerebral edema. The pulmonary edema was bilateral in two thirds of these patients and unilateral in one third. Arterial blood gases showed moderate to severe limitation of oxygen diffusion capacity. All patients recovered completely within a few days.