Intraperitoneal instillation versus wound infiltration for postoperative pain relief after cesarean delivery: A prospective, randomized, double-blind, placebo-controlled trial

Aim: To compare local anesthetic wound infiltration with intraperitoneal instillation of local anesthetic for analgesia after cesarean section under spinal anesthesia. Methods: This study was conducted on 150 pregnant women undergoing elective cesarean section under spinal anesthesia. Spinal anesthesia was performed with 7 mg isobaric bupivacaine and 15 μcg fentanyl. The patients were randomized into three groups of 50 patients each: Group local anesthetic wound infiltration (LWI): 20 ml local anesthetic solution (10 ml 0.5% bupivacaine and 10 ml 2% lidocaine mixture) was administered subcutaneous wound infiltration at the end of surgery prior to skin closure and 20 ml saline was instilled into the uterine peritoneal area before fascia closure. Group intraperitoneal local anesthetic (IPLA): 20 ml local anesthetic solution (10 ml 0.5% bupivacaine and 10 ml 2% lidocaine mixture) was instilled into the uterine peritoneal area and 20 ml saline was administered subcutaneous wound infiltration. Group Placebo: 20 ml saline was instilled into the uterine peritoneal area and 20 ml saline was administered local subcutaneous wound infiltration. Pain scores at rest and on movement, total fentanyl consumption at 24 h, maternal satisfaction, and the time to first analgesic request were recorded. Results: No statistically significant difference was observed in the postoperative pain scores at rest at 2, 12, and 24 h (p = 0.314, 0.343, and 0.735, respectively) and on movement at 12 and 24 h (p = 0.318 and 0.642, respectively) between the groups. The pain scores on movement at 2 h were significantly lower in Group IPLA compared with Group Placebo (p = 0.047). There were no significant differences between the groups in terms of total fentanyl consumption and the time to first analgesic request. Conclusion: The use of intraperitoneal instillation of bupivacaine and lidocaine reduces early the pain score on movement in women undergoing cesarean section under spinal anesthesia.