Minimal Tourniquet Pressure to Maintain Arterial Closure in Upper Limb Surgery

Abstract

Complications of the pneumatic tourniquet used during limb surgery result from excessive direct pressure. Traditional recommendations suggests parameters for maximum pressure and time limits rather than the minimal effective pressure to achieve a bloodless field. A clinical study was undertaken to evaluate the pneumatic tourniquet setting required for adequate haemostasis in the upper limb. The correlations between several possible influencing parameters (age, sex, arm fat thickness, extremity length, systolic, diastolic, and mean blood pressures) and the minimal pneumatic tourniquet pressure at which the peripheral pulse reappeared were studied in 50 patients undergoing surgery, using a Doppler stethoscope. The average Doppler Opening Pressure was 168.5 +/- 42.7 mmHg and the only significant clinical variable was the mean blood pressure. From these results an equation was derived to predict the minimal effective tourniquet pressure. The mean calculated tourniquet pressure was 202.3 +/- 34.2 mmHg, well below the 250 to 300 mmHg previously recommended. The technique consisted of inflating the tourniquet to a pressure of 300 mmHg, then reducing it to the calculated value. A bloodless field was maintained in all patients.

Safety and efficacy of a new tourniquet system

“…Levy et al [23] studied the correlations between several potential influencing parameters and the minimal tourniquet pressure in the upper limb using Doppler stethoscope, and blood pressure showed significant correlation; their formula is tourniquet pressure = (1.68 × mean arterial pressure) + 50 mmHg. They reported mean calculated minimal effective tourniquet pressures to be predicted were well below 250-300 mmHg previously recommended.…”

Tourniquet Usage in Upper Extremity Surgery

“…Levy et al 16 inflated a tourniquet to 300 mm Hg in 50 patients and measured average Doppler opening pressure during deflation. Using a safety margin of 50 mm Hg, the following calculation was derived: tourniquet pressure ϭ (1.68 ϫ mean arterial pressure) ϩ 50 mm Hg.…”

Tourniquet Cuff Pressure: The Gulf Between Science and Practice

“…This resulted in the average calculated tourniquet pressure of 202 mm Hg. 10 Reid et al measured the pressure at which peripheral pulse disappeared in 42 patients undergoing upper extremity surgery, and 50 mm Hg was added for the final tourniquet pressure. The average tourniquet pressure utilized in this cohort was 189.9 mm Hg, and the maximum was 255 mm Hg in one patient.…”

“…13 Similar results were reported by Levy who measured tourniquet pressure at which the pulse re-appeared on Doppler. 10 The average tourniquet pressure at which the pulse re-appeared was 168.5 mm Hg, and the authors derived an equation to predict the minimally effective tourniquet pressure, incorporating a 50 mm Hg safety zone. This resulted in the average calculated tourniquet pressure of 202 mm Hg.…”

“…A multitude of studies have been published in the English-language literature to define the optimum pressure. [7][8][9][10][11][12][13][14] In the upper limb, the standard guideline is to add 50 to 75 mm Hg to the systolic BP. This number depends on the systolic pressure and on the limb circumference, as higher limb circumference requires higher tourniquet pressures.…”