Comparison of Analgesic Efficacy Between Ultrasound-Guided Iliohypogastric/Ilioinguinal Nerve Block and Wound Infiltration Among Patients Undergoing Gynecologic Surgery: A Randomized Controlled Trial

Abstract

Background: Postoperative pain control is essential after surgery to ensure early mobilization, decrease the length of hospital stay and provide patient comfort. Local anesthetic (LA) wound infiltration has been used to reduce postoperative pain. In addition, the bilateral iliohypogastric/ilioinguinal nerve block (IINB) has been used to control pain in abdominal surgery but not in gynecologic or pelvic surgery.
 Objectives: This study aimed to evaluate the efficacy of ultrasound-guided iliohypogastric/ ilioinguinal nerve block compared with local anesthetic wound infiltration on postoperative pain control among patients undergoing gynecologic surgery through a Pfannenstiel incision.
 Methods: In this prospective, double-blinded, randomized controlled trial, 50 patients were allocated to either an IINB group (N=25) or LA group (N=25). In both groups, postoperative IV patient-control analgesia (PCA) was planned 24 hours, postoperatively. The primary outcomes were differences in pain score using a numerical rating scale (NRS) and morphine consumption between both groups immediately following 2, 4, 8, 12 and 24 hours, postoperatively.
 Results: The postoperative pain scores were significantly lower in the IINB group than in the LA group at all time points, with p <0.05. Total morphine consumption for 2-24 hours postoperative was significantly lower in the IINB group than in the LA group with p <0.001.
 Conclusion: Compared with LA wound infiltration, this study demonstrated that IINB provided better pain control and reduced the consumption of morphine in the first 24 hours among patients undergoing gynecologic surgery through a Pfannenstiel incision.