Background: Perioperative systemic lidocaine has been shown to have beneficial postoperative analgesic effects. The only previous study examining the use of lidocaine in the outpatient setting did not detect an opioid-sparing effect after hospital discharge. More importantly, it is unknown whether systemic lidocaine provides a better postoperative quality of recovery to patients undergoing ambulatory surgery. Our objective in the current study was to examine the effect of systemic lidocaine on postoperative quality of recovery in patients undergoing outpatient laparoscopic surgery.
Methods: The study was a prospective, randomized, double-blind, placebo-controlled clinical trial. Healthy female subjects were randomized to receive lidocaine (1.5 mg/kg bolus followed by a 2 mg/kg/h infusion until the end of the surgical procedure) or the same volume of saline. The primary outcome was the Quality of Recovery-40 questionnaire at 24 hours after surgery. A 10-point difference represents a clinically relevant improvement in quality of recovery based on previously reported values on the mean and range of the Quality of Recovery-40 score in patients after anesthesia and surgery. Other data collected included opioid consumption, pain scores, and time to meet hospital discharge. Data were compared using group t tests and the Wilcoxon exact test. The association between opioid consumption and quality of recovery was evaluated using Spearman ρ. P < 0.01 was used to reject the null hypothesis for the primary outcome.
Results: Seventy subjects were recruited and 63 completed the study. There were no baseline differences regarding subject and surgical characteristics between the study groups. Patients in the lidocaine group had better global quality of recovery scores compared with the saline group, median difference of 16 (99% confidence interval [CI], 2-28), P = 0.002. Patients in the lidocaine group met hospital discharge criteria faster than the saline group, mean difference of -26 minutes (95% CI, -6 to -46 minutes) (P = 0.03). After hospital discharge, subjects in the lidocaine group required less oral opioids, median difference of -10 (95% CI, 0 to -30) (oral milligrams morphine equivalents), than the saline group (P = 0.01). There was an inverse association between postoperative opioid consumption and quality of recovery (ρ = 0.64, P < 0.001).
Conclusions: Systemic lidocaine improves postoperative quality of recovery in patients undergoing outpatient laparoscopy. Patients who received lidocaine had less opioid consumption, which translated to a better quality of recovery. Lidocaine is a safe, inexpensive, effective strategy to improve quality of recovery after ambulatory surgery.
Trial registration: ClinicalTrials.gov NCT01250002.