Development of Personalized Tourniquet Systems Using a New Technique for Measuring Limb Occlusion Pressure

Abstract

A new technique has been developed to facilitate safer personalized tourniquet systems for surgery, using a unique dual-purpose tourniquet cuff that enables automatic measurement of tourniquet Limb Occlusion Pressure (LOP), while overcoming limitations inherent in manual and automatic techniques of LOP measurement. A study was performed to determine the accuracy of this new technique compared to LOP measured using a gold standard Doppler ultrasound technique. 252 pairs of LOP measurements were taken from upper and lower limbs of 143 surgical patients, enrolled from three different surgical clinics, using the new technique and the Doppler technique. LOP difference was defined as new technique reading minus Doppler technique reading. The mean LOP difference (new-Doppler) ± SD mmHg was ±0.56 ± 11.73 for all limbs (252 limbs), +0.99 ± 7.79 for upper limbs (134 upper), and +0.08 ± 15.03 for lower limbs (118 lower). Additional analysis was performed to further improve the performance of the new technique by noise detection and by development of rules allowing identification and removal of outlier data prior to completion of each LOP measurement. In this study, the additional analysis removed 3/252 pairs of LOP measurements and reduced the SD: mean LOP difference (new-Doppler) ± SD mmHg was improved to +0.30 ± 10.31 for all limbs (249 limbs), +0.99 ± 7.79 for upper limbs (134 upper), and -0.50 ± 12.62 for lower limbs (115 lower). We conclude that the new technique of LOP measurement has surgically acceptable accuracy comparable to LOP measurement by Doppler ultrasound. Additionally, the new technique may facilitate adoption of safer personalized tourniquet systems by incorporating inherent advancements over manual and automatic techniques of LOP measurement, including: elimination of a distal LOP sensor; reduced procedural complexity and surgical time; related improvements in the rate of success of LOP determination; and reduced direct and indirect costs.KeywordsTourniquetPersonalizedSafetySurgeryAdvancement