Further Studies of High Altitude Pulmonary Oedema

During the past ten years there has been a growing awareness of the occasional occurrence of acute pulmonary cedema as a result of exposure to high altitude. Early observations were made in the Peruvian Andes where a large number of people constantly travel from sea coast to altitudes up to 15,000 ft. (Lundberg, 1952; Bardales, 1955; Lizarraga, 1955; Lizarraga, 1957). A case report of acute pulmonary cedema occurring in a cross-country skier at high altitude in the Continental United States has been published by Houston (1960). Recently the entire problem has been re- viewed and 31 additional new cases have been described The data may be briefly summarized as follows: acute high altitude pulmonary cedema occurs in susceptible individuals who quickly go from sea level to altitudes of 9,000 to 15,000 feet. Acclimatized mountain residents who visit a low altitude area temporarily and then return to high altitude seem to be most suscept- ible. Most of the Peruvian patients were mountain residents who had spent from 1 to 4 weeks at sea level and then returned to the altitude. Young males under 19 and subjects who have experienced previous attacks of high altitude pulmonary cedema are also susceptible. Most of the episodes in mountaineers occurred upon initial exposure to high altitude, without adequate prior acclimatiza- tion. The symptoms usually consist of cough, dyspncea, weakness and hxmoptysis beginning 12 to 36 hours after arrival at a high altitude. Physical signs include pulmonary rales, cyanosis and tachy- cardia. Signs of infection are absent. Roentgenograms reveal pulmonary exudates which may be patchy or occasionally diffuse. The central pulmonary vessels are prominent. Cardiac enlargement is not present. Bed rest, oxygen administration, or removal to a lower elevation result in clinical recovery and clearing of the pulmonary exudate in 24 to 48 hours.