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

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.

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.

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.

The modified CAT demonstrated an upgraded pressure profile and hemorrhage control rate, potentially indicating its improved efficacy.