Slack Reducing Band Improves Combat Application Tourniquet Pressure Profile and Hemorrhage Control Rate.

Background: The Combat Application Tourniquet (CAT) is the tourniquet of choice in the Israeli defense forces. Applying the device loosely before windlass twisting is a main pitfall in CAT application. This study objective is to assess the effectiveness of a novel design modification of the CAT, aiming to prevent loose applications, by minimizing the slack. Methods: Using the HapMed leg tourniquet trainer, an above the knee traumatic amputation was simulated. Active duty combatants and Special Forces basic medics were randomly assigned to apply the modified (n = 67) or conventional CAT (n = 65) once. Applied pressure, hemorrhage control status, time to stop the bleeding, and estimated blood volume loss were measured. Results: Using the modified CAT, the mean (+/- SD) pressure applied was significantly higher compared to the conventional one (231.49 +/- 37.84 mm Hg vs. 213.31 +/- 45.51 mm Hg, p < 0.05). Hemorrhage control rate was 86.6% in the modified CAT group versus 67.7% in the conventional CAT group (p < 0.05). Analyzing only the applications that succeeded in hemorrhage control, blood loss (171.12 +/- 72.43 mL vs. 187.75 +/- 91.72 mL, p > 0.05) and time to stop bleeding (27.27 +/- 13.15 seconds vs. 27.5 +/- 11.25 seconds, p > 0.05) were similar. Conclusions: The modified CAT demonstrated an upgraded pressure profile and hemorrhage control rate, potentially indicating its improved efficacy.