A New Method for Estimating Arterial Occlusion Pressure in Optimizing Pneumatic Tourniquet Inflation Pressure

Abstract

To reduce pressure-related injuries resulting from pneumatic tourniquet use, the lowest possible inflation pressure is recommended. Arterial occlusion pressure (AOP) is a measure of the cuff pressure required to maintain a bloodless surgical field. However, its determination method is time consuming, requires operator skill, and is therefore seldom used in current practice. An AOP estimation can be made by knowing the pressure transmitted to the underlying soft tissues. We measured upper and lower extremity tissue pressures under the tourniquet cuff at 100, 200, and 300 mm Hg of tourniquet inflation pressures in 30 anesthetized living adult patients. All patients received general anesthesia with neuromuscular relaxation. A Stryker intra-compartmental pressure monitor was used to measure tissue pressures under the tourniquet cuff. In all patients, the soft tissue pressures were consistently lower than the applied tourniquet inflation pressures. Our results revealed tissue padding coefficients for extremities 20 to 75 cm in circumferences. An estimation method of AOP was developed [AOP = (systolic blood pressure + 10)/Tissue padding coefficient]. The new AOP estimation method may be a simple, rapid, and clinically practical alternative to the AOP determination method.

Effects of Tourniquet Pressure on Rehabilitation Outcomes in Patients Undergoing Total Knee Arthroplasty

“…Doppler stethoscope or digital plethysmography, has been suggested ( Mohler et al, 1999 ;Tuncali et al, 2003Tuncali et al, , 2006. Further studies to clinically assess the outcomes of tourniquet application at lower infl ation pressures are indicated during TKA surgery to develop this hypothesis (Smith & Hing, 2010).…”

Vein occlusion by upper versus forearm tourniquets in humans

“…A possible explanation for this finding has to do with the circumference of the limb. A recent study found that tissue pressure measured near the bone directly under the cuff was less than cuff pressure, and that the difference increased with the circumference of the extremity, an effect thought to be due to "tissue padding" [4]. This effect would be more pronounced in the larger upper extremities of our subjects, possibly accounting for the lower venous pressures observed with upper arm cuffs.…”

“…This effect would be more pronounced in the larger upper extremities of our subjects, possibly accounting for the lower venous pressures observed with upper arm cuffs. The nonlinear regression equation developed by Tuncali et al [4] predicts tissue pressure of 80% to 85% of cuff pressure in extremities with a circumference between 24 and 31 cm. Our vein occlusion pressures were in the range of 66% to 85% of cuff pressure.…”

Pressures secondary to circumferential digital dressings in clay models

“…Tuncali et al [20] reported a method for estimation of the arterial occlusion pressure; according to these principles the pressure necessary to prevent digital blood flow ranges from 110 to 140 mmHg. In this study, the average pressures in the rolled and untightened bandage group along the live finger were significantly higher than those for the adult finger model.…”