An Adaptive Tourniquet for Improved Safety in Surgery

The increasingly recognized inability of the current generation of pneumatic tourniquets to control pressure with adequate accuracy, reliability, and stability has been associated with continuing reports of tourniquet-related injuries, incidents, and hazards. Moreover, the labor-intensiveness and operating costs associated with the use of current types of pneumatic tourniquets have significant cost implications for hospitals. To a large extent, the recent development of a microprocessor-based tourniquet capable of safely and accurately maintaining a desired pressure, and capable of simultaneously performing other functions such as detection of alarm conditions, has reduced these hazards and operating-cost implications. Furthermore, the availability of a microprocessor-based tourniquet has facilitated the development of the adaptive tourniquet described in this paper, in which the pressure in a tourniquet cuff is changed throughout a surgical procedure as a function of the patient's changing intraoperative systolic pressure, thus approximating the minimum safe pressure necessary to maintain a bloodless field for surgery. While the use of an adaptive tourniquet, rather than just a microprocessor-based tourniquet set at a constant pressure may not be necessary in most cases, it promises to have significant value in certain surgical procedures and for patients who may be at greater risk of tourniquet-induced complications. Also, the lower average pressures possible through the use of an adaptive tourniquet may permit the evolution of surgical techniques of longer duration without a concomitant increase in the risk of tourniquet-induced complications.