High Altitude Illness

Abstract

High-altitude illnesses include acute mountain sickness (AMS), high-altitude cerebral edema (HACE), and high-altitude pulmonary edema (HAPE). Gradual ascent provides the optimal means of avoiding high-altitude illness; thus, public education regarding gradual ascent plays an important role in reducing the morbidity and mortality of serious altitude illness. This review summarizes the primary types of acute altitude sickness, acclimatization to high altitude, assessment and stabilization, diagnosis, treatment and disposition, prophylaxis, and outcomes for patients with high-altitude illness. Figures show physiologic changes leading to acclimatization to high altitude, HAPE physiology, the ‘bar-code sign’ indicating the presence of pneumothorax, the ‘waves on a beach’ sign indicating the absence of pneumothorax, images of lungs with and without edema on ultrasonography, a chest x-ray of HAPE, and a photograph of a portable hyperbaric treatment bag. Tables list rules to avoid serious altitude illness; initial assessment of the new patient with potential high-altitude illness; differential diagnosis, diagnostic criteria, and treatments for AMS, HACE, and HAPE; the Lake Louise score for establishing AMS severity; and prophylaxis for cerebral forms of altitude illness. Videos show the use of a high-frequency linear array probe to assess pneumothorax. This review contains 8 highly rendered figures, 14 tables, 3 videos, and 68 references.