Purpose: Tourniquet cuff pressures in paediatric patients are commonly set at standard pressures. Recent evidence on adult subjects has shown that safer and more effective cuff pressures can be achieved by measuring limb occlusion pressure (LOP) and using a wide, contour cuff. There is little evidence validating these techniques in children. The primary objective of this study was to evaluate if a difference in tourniquet cuff pressure can be achieved in a paediatric population using a wide contour cuff in conjunction with measured LOP when compared to a standard cuff and pressure.

Method: Subjects aged 10 to 17 years that underwent anterior cruciate ligament repair were included and ran-domised into either the control group or the experimental ‘LOP’ group using variable block randomisation. The tourniquet cuff was inflated to 300 mmHg in the control group or to the recommended tourniquet pressure based on LOP measurement in the LOP group. The surgeon was blinded to cuff selection, application and pressure throughout the surgical procedure. Immediately following the surgical procedure, the surgeon rated the quality of the bloodless field on a visual analogue scale (VAS). This study was powered as an effectiveness trial and intention to treat analysis was used.

Results: Following a planned interim analysis at midpoint, complete data was recorded for 11 patients (control group) and 10 patients (LOP group). The quality of the surgical field was not different between groups (p= 0.053). There was a statistically significant difference in mean cuff pressure between the control group (300 mmHg) and the LOP group (151 mmHg) (p < 0.001). We ran the same analysis comparing the LOP data to hypothetical control data of 250 mmHg and our results remained statistically significant (p < 0.001).

Conclusion: The use of an automatic LOP measurement with the use wide contour cuffs can significantly reduce average tourniquet cuff pressures in paediatric patients compared to typical practice of 300 mmHg or 250 mmHg without compromising the quality of the surgical field.

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.