Does Pain Have a Role When It Comes to Tourniquet Training?

One of the greatest conundrums with tourniquet (TQ) education is the use of an appropriate surrogate of hemorrhage in the training setting to determine whether a TQ has been successfully used. At our facility, we currently use loss of audible Doppler signal or loss of palpable pulse to represent adequate occlusion of vasculature and thus successful TQ application. We set out to determine whether pain can be used to indicate successful TQ application in the training setting.

Three tourniquet systems (a pneumatic tourniquet, Combat Application Tourniquet® [C-A-T], and Stretch Wrap and Tuck Tourniquet™ [SWAT-T]) were used to occlude the arterial vasculature of the left upper arm (LUA), right upper arm (RUA), left forearm (LFA), right forearm (RFA), right thigh (RTH), and right calf (RCA) of 41 volunteers. A 4MHz, handheld Doppler ultrasound was used to confirm loss of Doppler signal (LOS) at the radial or posterior tibial artery to denote successful TQ application. Once successful placement of the TQ was noted, subjects rated their pain from 0 to 10 on the visual analog scale. In addition, the circumference of each limb, the pressure with the pneumatic TQ, number of twists with the C-A-T, and length of TQ used for the SWAT-T to obtain LOS was recorded.

All 41 subjects had measurements at all anatomic sites with the pneumatic TQ, except one participant who was unable to complete the LUA. In total, pain was rated as 1 or less by 61% of subjects for LUA, 50% for LFA, 57.5% for RUA, 52.5% RFA, 15% for RTH, and 25% for RCA. Pain was rated 3 or 4 by 45% of subjects for RTH. For the C-A-T, data were collected from 40 participants. In total, pain was rated as 1 or less by 57.5% for the LUA, 70% for the LFA, 62.5% for the RUA, 75% for the RFA, 15% for the RTH, and 40% for the RCA. Pain was rated 3 or 4 by 42.5%. The SWAT-T group consisted of 37 participants for all anatomic locations. In total, pain was rated as 1 or less by 27% for LUA, 40.5% for the LFA, 27.0% for the RUA, 43.2 for the RFA, 18.9% for the RTH, and 16.2% for the RCA. Pain was rated 5 by 21.6% for RTH application, and 3 or 4 by 35%.

The unexpected low pain values recorded when loss of signal was reached make the use of pain too sensitive as an indicator to confirm adequate occlusion of vasculature and, thus, successful TQ application.