Some patients live after trauma: Re-examining the lethality of vertical deceleration injuries

Abstract

Background Vertical deceleration injury is a unique urban phenomenon of blunt injury resulting in significant morbidity and mortality. Since evaluations began in the 1940s and more extensively in the 1980s through 2005, the fall height at which 50% of patients are expected to die (LD50) has been consistently estimated to be 40 ft (12.1 m) and historical reports suggest no patients were able to survive a fall greater than 50 ft (15.2 m). The aim of this study was to determine the current LD50 or survivable free fall height in comparison to historical reports. Study design The trauma database at an urban level one trauma center was reviewed for all falls from a significant height from January 2010 to December 2015. The data were stratified based upon the height of the fall. The height at which 50% of patients were expected to die was determined by logistic non-linear regression line plot. Results In total, 110 patients were identified, with 97 meeting criteria for inclusion into the study. Twelve patients fell from 60 ft (18.2 m) with six survivors. The calculated LD50 was 48 ft (14.8 m) when the heights of a story and floor were standardized to 10 ft (3 m); if the height was increased to 12 ft (3.7 m) per story, the LD50 would be 68 ft (20.1 m). Conclusions The survivable height, as well as the LD50 of vertical free falls, has increased as compared to previous studies. We assume that this is attributable to the advances in diagnostic imaging, interventional radiology therapies, critical care, and field management of these patients. A fall from 80 ft (24 m) exceeds the maximum threshold of force that the human body can withstand.