Analgesic effects of a 5% lidocaine patch after cesarean section: A randomized placebo-controlled double-blind clinical trial

Abstract

Study objectiveThis study aimed to evaluate the analgesic effects of a 5% lidocaine patch in acute postoperative pain after cesarean section. DesignThis is a prospective, randomized, double-blind study. SettingAfter surgery, active and placebo patches were applied in the operating room, and patients were evaluated during their stay at the postoperative recovery room and at the hospital ward. PatientsSeventy-two women (18 years of age or older and American Society of Anesthesiologists status II) scheduled for cesarean section under spinal anesthesia were enrolled in the study. InterventionsPatients were randomly assigned to an intervention or placebo group. According to the assigned group, a 5% lidocaine patch or a placebo patch was applied 1 cm above and below the Pfannenstiel incision after the surgery. MeasurementsThe primary outcome was the pain score, evaluated using an 11-point numerical verbal scale in the first 36 h postoperatively. Secondary outcomes were the quality of recovery 24 h after surgery, consumption of rescue opioids, and the presence of adverse effects. Main resultsSixty-five women completed the study. The pain score was lower in the lidocaine group at 6 h (lidocaine group: 2.16 ± 1.71, placebo group: 3.21 ± 2.25; p = 0.031), 12 h (lidocaine: 1.58 ± 0.81, placebo: 2.24 ± 0.74; p = 0.001), 24 h (lidocaine: 0.74 ± 0.89, placebo: 1.94 ± 1.39; p < 0.0001), and 36 h (lidocaine: 0.48 ± 1.03, placebo: 1.68 ± 0.94; p = 0.001) after surgery. There were no differences in secondary outcomes during the follow-up period. ConclusionThe lidocaine patch reduced pain scores compared to placebo in the first 36 h after the surgery, despite no influence over opioid consumption, quality of recovery, or incidence of side effects.