Combat application tourniquet (CAT) eradicates popliteal pulses effectively by correcting the windlass turn degrees:...

We aimed to define an ideal range of windlass turn degrees for 100 % success rates within the study population.

CAT was applied at mid-thigh level. Data included age, lower extremity circumference (LEC), body mass index (BMI), and mean arterial pressure (MAP). Windlass turn degrees were measured in failed and successful participants. The failed participants' windlass mechanisms were twisted until the popliteal artery was occluded. Failure to success and additional turn degrees to secure the windlass mechanism of CAT was determined. Doppler ultrasound was used to examine the popliteal artery blood flow.

145 servicemen have participated in the study. Initially, 70 % successfully applied CAT. There was no statistically significant difference in BMI and MAP values between successful and failed participants. The mean LEC for failed and successful applications were 57.5 ± 4 and 56.8 ± 4, respectively. The required turn degrees for success ranged between 45° and 270°. After correction, the cumulative success rate of 93 and 100 % was reached at 990° and 1170° overall turn degrees.

In order to adequately stop limb hemorrhage, soldiers should be taught their optimal turn degrees.