Clinical features of patients with high-altitude pulmonary edema in Japan.

Clinical studies were performed in 27 consecutive patients with high-altitude pulmonary edema who were transported from the mountains to Shinshu University Hospital, Matsumoto, Japan. The altitude of onset was 2,680 m to 3,190 m above sea level. Symptoms included marked dyspnea, cough, and stridor. Physical findings included cyanosis, tachycardia, and rales. Neurologic disturbances, which were seen in 17 patients, included headache, vomiting, memory disturbance, clouding of consciousness, or coma. Chest roentgenograms revealed patchy infiltrates throughout the pulmonary fields, often in an asymmetric pattern, and enlargement of the right ventricle. Hemodynamic studies by right cardiac catheterization showed that high-altitude pulmonary edema was noncardiogenic. Scintiscans of the lungs with technetium-99m-macroaggregated albumin (99mTc-MAA) performed in one patient showed decreased perfusion of 99mTc-MAA in the area of infiltrates. Pulmonary edema fluid collected through the endotracheal tube in two patients was rich in protein. Computerized tomograms of the brain showed small ventricles and cisterns, disappearance of sulci, and diffuse low density of the cerebrum, indicating cerebral edema in eight of nine cases. Retinal hemorrhage and papilledema were observed in five patients.