Inconsistent Tourniquet Practice and Tourniquet Pain in Patients Undergoing Foot and Ankle Surgery
Presenting Author Details: Lisa MacBeth, MD ([email protected])
Co-Authors: Haley Fuller, MD; Promil Kukreja, PhD, MD; and Ayesha Bryant, MSPH, MD
Introduction: Pneumatic tourniquets improve operative conditions by limiting blood loss, improving structure visualization and reducing operating room times. Neuromuscular injuries from tourniquets are well known, as compression of nerves can result in microvascular congestion and edema, inadequate tissue perfusion, and axonal degeneration.1 Post-tourniquet syndrome is characterized by a swollen, stiff and pale limb with paresis and paresthesias, and in the perioperative period can be mistaken for inadequate analgesia or perioperative complication from a peripheral nerve block.1 Recommended tourniquet inflation pressures are based on either systolic blood pressure (SBP) measurements or limb occlusion pressures, however SBPs do not reliably correlate with limb occlusion pressures, likely because other factors including patient age; extremity shape and size; and cuff dimensions play a role.1,2 Recommendations based on SBP recommend inflation to 90-150 mmHg greater than SBP for lower extremity procedures, with a maximum ≤300 mmHg for <2.5 hours.3
Materials and Methods: After IRB approval, we completed a retrospective cohort study of patients > 18 years of age who had foot and ankle surgery under general anesthesia with intraoperative tourniquet use. All patients had regional anesthesia blocks preoperatively. Exclusion criteria included a history of daily opioid use greater than 30 oral morphine equivalents for greater than thirty days. The patient’s baseline SBP; tourniquet time and pressure, including deflation time and re-inflation pressure and time; intraoperative opioid consumption; and length of stay were obtained.
Results: Between August 1, 2015 and December 1, 2015, 130 met inclusion criteria. Only 2% of the tourniquet pressures in our study were aligned with published recommendations based on SBP, with the remaining 98% inflated to higher than recommended pressures (Figure 1). Long tourniquet times (≥ 90 minutes) were associated with greater intraoperative opioid use than short tourniquet times (≤ 90 minutes) (19 mg ± 22 mg vs. 5 mg ± 11.6 mg; p <0.001) (Table 1). Tourniquet duration and PACU length of stay had a positive association (R2 = 0.4) (Figure 2).
Discussion: Although there are published guidelines for tourniquet pressures, they are inconsistent and not confirmed to be relevant clinically. Prolonged tourniquet times at high pressures not based on limb occlusion pressure, as observed in our study, lead to increased pain and opioid use and prolonged time in PACU. Basing tourniquet pressures on limb occlusion pressures could likely improve the safety margin of tourniquets, however randomized studies need to be completed to confirm this.