Abstract
Introduction: Traumatic asphyxia is a form of trauma caused by strong pressure on the chest leading to respiratory failure, hypoxic encephalopathy, and eventual death. The relationship between these medical events and physical conditions and parameters, including compression area, magnitude of the load, and load time, remains unclear. The purpose of this study was to estimate the conditions of thoracoabdominal compression (magnitude of the load, load time) leading to respiratory failure.
Subjects and Methods: Subjects comprised five healthy men. Average body weight was 61.1 ± 3.7kg. Three compression patterns on the thoracoabdominal area were achieved by applying loads (Pattern A: chest and abdomen: 50kg; Pattern B: 40kg; and Pattern C: 30kg), and blood pressure, heart rate, respiratory rate, vital capacity, tidal volume and respiratory phase were observed over time. In addition, we calculated breathing intolerance index (BITI) and estimated the time to respiratory failure for each pattern.
Results: In Pattern A, respiratory rate increased over time, and tidal volume was reduced. In Patterns A, B, and C, BITI reached the critical zone of 0.15 at 32, 42, and 81 min, respectively. Respiratory failure was estimated to develop 45 min after reaching this critical zone, meaning 77, 87, and 126 min after loading, respectively.
Discussion: This study added compression of the abdomen in addition to compression of the chest although not in the previous study. Despite the thoracoabdominal compression force only being in 30kg, subjects were estimated to reach respiratory failure due to respiratory muscle fatigue. In elderly individuals and children, breathing resistance would tend to be even lower. From the perspectives of both emergency medicine and engineering design of spaces for its prevention, elucidation of the mechanisms and parameters of traumatic asphyxiation is important, and further research is needed.
