Abstract
Haemorrhage is the main cause of preventable death on the modern battlefield. As IEDs in Afghanistan become increasingly powerful, more proximal limb injuries occur. Significant concerns now exist about the ability of the CAT tourniquet to control distal haemorrhage following mid thigh application.
Aim
To evaluate the efficacy of the CAT windlass tourniquet in comparison to the newer EMT pneumatic tourniquet.
Method
Serving soldiers were recruited from a military orthopaedic outpatient clinic. Participants' demographics and blood pressure were recorded and a short medical history obtained to exclude any arteriopathic conditions. Doppler ultrasound was used to identify the popliteal pulses bilaterally. The CAT was randomly self-applied by the participant at mid thigh level and the presence or absence of the popliteal pulse on Doppler was recorded. The process was repeated on the contralateral leg with the CAT now applied by a trained researcher. Finally the EMT tourniquet was self applied to the first leg and popliteal pulse change Doppler recorded again.
Results
40 consecutive patients were invited to participate in the study. 15 declined to participate. 1 was excluded via pre-determined exclusion criteria.
A total of 24 participants were recruited. The self applied CAT occluded popliteal flow in only 4 subjects (16.6%). The CAT applied by a researcher occluded popliteal flow in 2 subjects (8.3%). The EMT prevented all popliteal flow in 18 subjects (75%)
Discussion
This study demonstrates that the CAT tourniquet is ineffective in controlling arterial blood flow when applied at mid thigh level. The EMT was successful in a significantly larger number of participants.
