A RANDOMIZED PROSPECTIVE STUDY COMPARING THE QUALITY OF SURGICAL FIELDS RESULTING FROM AUTOMATICALLY DETERMINED TOURNIQUET CUFF PRESSURE VERSUS SURGEON CHOSEN TOURNIQUET CUFF PRESSURE.

Abstract

Patients were randomized between surgeon chosen pressure (control) and an automatically determined tourniquet pressure(study) group. Of the study group 94/106 (88.7%) had good to excellent fields compared to the control group where 100/132 (75.8%) had good to excellent fields (p< 0.05). In the study group, 5% failed to obtain an automatic pressure. Of the remainder, the average tourniquet pressure was 198 +/− 20.2 mHg compared to 259.6 +/− 4.4 mmHg for the control group (p< 0.0001). The automatic measurement of limb occlusion pressure resulted in better operative fields at a lower pressure.

To compare the quality of the operative field that results from using an automatic limb occlusion pressure measurement (study group) versus the tourniquet cuff pressure chosen by the surgeon (control group).

A module allowing rapid determination of tourniquet pressure from limb occlusion pressure was attached to a Zimmer ATS tourniquet machine. Using a coin toss, patients were randomized to the study or control groups. All patients underwent elective foot and ankle operations using a wide contoured tourniquet cuff.

Of two hundred and forty-three patients, one hundred and twelve were assigned to the study (automatic) group and one hundred and thirty-two to the control (surgeon selected) group. Six patients (5.4%) failed to obtain a limb occlusion pressure measurement due to anatomical constraints (toe or thigh shape) or equipment problems, leaving one hundred and six in the study group. The average measurement time to determine limb occlusion pressure was 20 +/− 6 seconds. The mean tourniquet pressure for the study group was 198.5 +/−20.2 mmHg, and 259.6 +/−4.4 mmHg for the control group (p< 0.0001). Of the study group 94 (88.7%) had good to excellent fields compared to the control group where one hundred (75.8%) had good to excellent fields (p< 0.05).

An automatically determined tourniquet pressure reduced the tourniquet pressure and improved the incidence of good to excellent operative fields compared to surgeon chosen pressures. The distribution curve of automatically determined tourniquet pressure indicates that 16% of patients will have a failed field if a standard pre-selected pressure of 250 mmHg is always chosen, in part explaining why pre-selected pressure may cause a poorer operative field.