Wilderness and Rescue Medicine 8th Edition

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Section V: Environmental Medicine

Chapter 19 Review: Altitude Illness

• The basic mechanism for altitude illness is swelling caused by hypoxia. • Mild symptoms are caused by short-term compensation efforts and mild swelling. Serious problems are caused by severe swelling. • High-altitude cerebral edema (HACE) is caused by capillary leakage of fluid into the brain, resulting in increased intracranial pressure. • High-altitude pulmonary edema (HAPE) is the result of capillary leakage of fluid into the alveoli, causing respiratory distress. • The early symptoms of HACE are the characteristic headache, loss of appetite, and nausea associated with the slight increase in ICP. • The ideal treatment of HACE is immediate descent. If that is not possible, treatment on scene includes rest, pain medication, supplemental oxygen, and fluid to maintain hydration. • The symptoms of severe HACE include headache, vomiting, and altered mental status. It can be confused with those of other problems such as hypoglycemia, dehydration, hypothermia, hyper- thermia, and simple exhaustion. • The early symptoms of HAPE are shortness of breath on exertion, fatigue, and sometimes a dry cough. It can also produce a low-grade fever. • As pulmonary edema worsens, a HAPE patient experiences shortness of breath, even at rest, and a persistent cough. Crackles are audible with a stethoscope or an ear to the chest. • The ideal treatment for HAPE is supplemental oxygen and immediate descent. If that is not possible, treatment on scene includes medications, PPV, and supplemental oxygen. • Expeditions traveling above 3,000 meters should consider carrying prophylactic and emergency medications and the use of a portable hyperbaric chamber. • Altitude makes the symptoms of an existing illness worse. The reduction in available oxygen as well as the reduced protective effects of the atmosphere predispose people to other problems as well.