BASE Jumping in the Lauterbrunnen Valley: A Retrospective Cohort Study from 2007 to 2016

Background: BASE jumping, and especially BASE jumping with the help of wingsuits, is considered one of the most dangerous airborne sports. The valley of Lauterbrunnen in Switzerland has become infamous for the large number of BASE jumps and the high rate of accidents and fatalities. The aim of this study was to evaluate the morbidity and mortality of BASE jumping, to determine the severity of injuries and injury patterns of BASE jumping accidents and to compare preclinical assessment with clinical diagnoses to detect under- or overtriage.

Methods: This retrospective, descriptive cohort study covers a period of 10 years (2007-2016). The evaluation covered all BASE jumping incidents in the valley of Lauterbrunnen that required either a helicopter mission by the local HEMS (Helicopter Emergency Medical Service) company of Lauterbrunnen, Air Glaciers, or medical care in the regional hospital, the level I trauma centre or the medical practice of the local general practitioner. Besides demographic data, experience in BASE jumping and skydiving as well as BASE jumping technique(s) and details about the rescue missions were collected. The medical data focused on the severity of injuries, as expressed by the National Advisory Committee of Aeronautics (NACA) score in the prehospital assessment as well as the Abbreviated Injury Scale (AIS) and Injury Severity Score (ISS) retrieved from the clinical records in the hospital or medical practice setting.

Results: The patients were predominantly young, experienced male BASE jumpers. Morbidity (injury risk) ranged from 0.05% to 0.2%, and fatality risk from 0.02% to 0.08%. Undertriage was low, with only two cases. Overtriage was significant, with 73.2% of all NACA 4-6 cases not qualifying for major trauma.

Conclusions: BASE jumping remains a high-risk sport and is associated with significant rates of injuries and fatalities. Comparison with previous studies indicated that the injury rate may have decreased, but the fatality rate had not. In this known BASE jumping environment, prehospital assessment appears to be good, as we found a low undertriage rate. The high overtriage rate might be an expression of physicians' awareness of high-velocity trauma mechanisms and possible deceleration injuries.