Laboratory testing of emergency tourniquets exposed to prolonged heat
Background:
Environmental exposure of tourniquets has been associated with component damage rates, but the specific type of environmental exposure, such as heat, is unknown. Emergency-tourniquet damage has been associated with malfunction and loss of hemorrhage control, which may risk loss of life during first aid. The purposes of the study are to determine the damage rate of tourniquets exposed to heat and to compare the rate to that of controls.
Methods:
Three tourniquet models (Combat Application Tourniquet(®); SOF(®) Tactical Tourniquet; Ratcheting Medical Tourniquet(®)) were tested using a manikin (HapMed Leg Tourniquet Trainer; www.chisystems.com) that simulates extremity hemorrhage. The study group of 15 tourniquets (five devices per model, three models) was exposed to heat (oven at 54.4° C [130° F] for 91 days), and 15 tourniquets similarly constituted the control group (unexposed to heat). Damage, hemorrhage control, distal pulse stoppage, time to effectiveness, pressure (mmHg), and blood loss volumes were measured.
Results:
Three tourniquets in both groups had damage not associated with heat exposure (p = 1). Heat exposure was not associated with change in effectiveness rates (p = .32); this lack of association applied to both hemorrhage control and pulse stoppage. When adjusted for the effects of user and model, the comparisons of time to effectiveness and total blood loss were statistically significant (p < .0001), but the comparison of pressure was not (p = .0613).
Conclusion:
Heat exposure was not associated with tourniquet damage, inability to gain hemorrhage control, or inability to stop the distal pulse.
