Mountaineering medical events and trauma on Denali, 1992-2011

Denali (Mt. McKinley) is the tallest mountain in North America and a popular climbing destination for high altitude mountaineering expeditions. National Park Service (NPS) personnel care for and manage medical incidences and traumatic injuries for mountaineers each year. We retrospectively examined NPS medical reports from the climbing seasons of 1992-2011. Medical complaints, diagnoses, treatment, provider training, and overall numbers of injuries and illness were analyzed. Fatalities were included only if they were cared for by NPS medical personnel prior to death. Of the 24,079 climbers on Denali during this period, 831 (3.5%) required medical assistance from the NPS. There were 819 diagnoses; 502 were due to medical illness and 317 were traumatic injuries. Patient encounters occurred most frequently (71%) at the 4328 m camp. Frostbite was the most common individual diagnosis (18.1%), while altitude-related syndromes were the most common illness category (29%). Most patients (84%) were treated and released to descend without additional intervention, whereas 11% needed air evacuation, and 4% needed another type of NPS assistance to descend. The only fatality in this series was caused by traumatic brain injury due to a climbing fall. A broad variety of medical complaints were evaluated and treated by NPS personnel, most commonly altitude related problems and frostbite. The results of the study will enhance the awareness of potential illness and injuries encountered by medical providers participating in high altitude mountaineering expeditions. Additionally, providers responsible for evaluating mountaineers prior to their expeditions can educate them on the spectrum of physical and environmental conditions that increase the chances of illness or injury. This ideally will decrease the incidence of morbidity on both Denali and other high altitude mountaineering destinations.