Effects of Tourniquet Features on Application Processes Times.

Background: We investigated emergency-use limb tourniquet design features effects on application processes (companion paper) and times to complete those processes (this paper).

Methods: Sixty-four appliers watched training videos then each applied all eight tourniquets: Combat Application Tour- niquet Generation 7 (CAT7), SOF™ Tactical Tourniquet-Wide Generation 3 (SOFTTW3), SOF™ Tactical Tourniquet-Wide Generation 5 (SOFTTW5), Tactical Mechanical Tourniquet (TMT), OMNA Marine Tourniquet (OMT), X8T-Tourniquet (X8T), Tactical Ratcheting Medical Tourniquet (Tac RMT), and RapidStop Tourniquet (RST). Application processes times were captured from videos.

Results: From "Go" to "touch tightening system" was fastest with clips and self-securing redirect buckles and without strap/redirect application process problems (n, median seconds: CAT7 n=23, 26.89; SOFTTW3 n=11, 20.95; SOFTTW5 n=16, 20.53; TMT n=5, 26.61; OMT n=12, 25.94; X8T n=3, 18.44; Tac RMT n=15, 30.59; RST n=7, 22.80). From "touch tightening system" to "last occlusion" was fastest with windlass rod systems when there were no tightening system understanding or mechanical problems (seconds: CAT7 n=48, 4.21; SOFTTW3 n=47, 5.99; SOFTTW5 n=44, 4.65; TMT n=38, 6.21; OMT n=51, 6.22; X8T n=48, 7.59; Tac RMT n=52, 8.44; RST n=40, 8.02). For occluded, tightening system secure applications, from "touch tightening system" to "Done" was fastest with self-securing tightening systems tightening from a tight strap (occluded, secure time in seconds from a tight strap: CAT7 n=17, 14.47; SOFTTW3 n=22, 10.91; SOFTTW5 n=38, 9.19; TMT n=14, 11.42; OMT n=44, 7.01; X8T n=12 9.82; Tac RMT n=20, 6.45; RST n=23, 8.64).

Conclusions: Suboptimal processes in- crease application times. Optimal design features for fast, occlusive, secure tourniquet applications are self-securing strap/ redirect systems with an easily identified and easily used clip and self-securing tightening systems.