Forearm and Arm Tourniquet Tolerance

Abstract

Background: In distal upper extremity surgeries, there can be a choice to use an upper arm or forearm tourniquet. This study examines discomfort and tolerance in healthy volunteers to determine whether one is more comfortable.

Methods: Forty healthy, study participants were randomized to an upper extremity laterality and site. Tourniquets were inflated to 100 mm Hg over systolic blood pressure. Participants experienced an upper arm and a forearm tourniquet sequentially. Visual analog scores (VAS) were recorded at 2-minute intervals. Time until request and VAS at tourniquet deflation were recorded. Time until the complete resolution of paresthesias was also recorded. Participants subjectively stated which tourniquet felt more comfortable.

Results: Tourniquets were inflated longer on the forearm than the upper arm (mean 16.1 minutes versus 12.2 minutes; P < 0.0001). VAS at tourniquet removal was not different between the sites (means 7.3 and 7.3) (P = 0.839). Time until paresthesia resolution after the tourniquet was deflated was not different (means 8.1 and 7.7 minutes) (P = 0.675). Time until paresthesia resolution was proportional to tourniquet inflation time for both sites (regression coefficient 0.41; P < 0.00001). Participants found the forearm more comfortable (95% confidence interval, 0.63 to 0.92).

Conclusion: Forearm placement allows the tourniquet to be inflated for an average of 4 minutes longer. Forearm tourniquet is subjectively more comfortable.

Figure 1

Bar diagram showing that tourniquet tolerance time varied significantly by the anatomic site with forearm tourniquets tolerated by participants for longer (mean 16.1 minutes, range 3.5 to 38.1 min, SD 9.2) than tourniquets on the upper arm (mean of 12.2 min, range: 3.1 to 32.9 min, SD 7.9) (P < 0.0001) (A). In both anatomic sites, similar VAS prompted participants to request tourniquet removal, despite different times of inflation (forearm mean 7.3, SD 1.36; upper mean 7.32, SD 1.19) (P = 0.839) (B). VAS = visual analog scores.

Figure 2

Graph showing that the time for paresthesias to completely resolve after tourniquet removal was not significantly different between forearm (mean 8.07; SD 5.07) and upper arm (mean 7.74, SD 4.47) locations (P = 0.675). For both anatomic sites, a regression coefficient of 0.41 is statistically significant (0 < 0.0001), indicating that it takes 0.41 minutes (or approximately 25 seconds) for paresthesia resolution after each minute of tourniquet inflation.