A double-blinded randomised controlled study to investigate the effect of intraperitoneal levobupivacaine on post laparoscopic pain

Background: Laparoscopic surgery is the cornerstone of modern gynaecological surgery, with shorter hospital stays and a quicker return to normal activities. However postoperative pain remains problematic. No strategy to reduce phrenic nerve irritation, including heating or humidifying the insufflating gas, alternatives to CO2, and intraperitoneal analgesics, has shown superiority. Methods: 100 women undergoing laparoscopic surgery were randomly allocated, having either 40ml of 0.25% levobupivacaine or 40ml 0.9% sodium chloride solution administered into the peritoneal cavity following surgery. The patients and the main researcher were blinded. All women received standardised anaesthetic and laparoscopic technique, and postoperative pain control including nursing position and nature of analgesia. Postoperative pain was assessed 3 hours, 8 hours, day 1 and day 4/5 postoperatively. Results: 100 patients were recruited undergoing surgery for benign causes aged 19-73(mean 40.3 +/- 13). There was no difference between the groups for age(p=0.64) or length of operation(p=0.56). There were no adverse events related to use of intraperitoneal instillation. There was a significant reduction in shoulder-tip pain scores in the levobupivacaine group at 3 hours(p=0.04). Furthermore, there was a significant reduction in wound-pain scores in the levobupivacaine group at 8hrs(p=0.04) and at day 4(p=0.04). No difference was found in pelvic pain between the two groups. No significant difference was found in the use of post-operative analgesia. Conclusions: Intraperitoneal instillation of 40ml of levobupivacaine has some benefit in reducing postoperative pain and need for analgesia in the initial hours following gynaecological surgery. However, further well-designed randomised control trials are required to decide the optimum route and concentration of administering local anaesthetic.