Evaluation of intraperitoneal bupivacaine for postoperative analgesia in patients undergoing laparoscopic cholecystectomy: a prospective randomized trial

Background: This study was conducted to evaluate the quality and duration of postoperative analgesia with intraperitoneal instillation of 0.5% bupivacaine after laparoscopic cholecystectomy. Methodology: In a prospective, randomized, double blind, placebo controlled study, 60 ASA grade I and II female patients of age groups 20-60 yrs, undergoing elective laparoscopic cholecystectomy under general anesthesia were equally distributed into two groups. In Group B (study group) 20 ml of 0.5% bupivacaine and in Group S (placebo group) 20 ml of normal saline were injected intraperitoneally after gall bladder extraction. A visual analogue scale which consisted of a 10 cm scale with markings at equal intervals, where 0 represented no pain and 10 represented worst imaginable pain, was used to assess postoperative pain at predetermined time intervals. Two way repeated ANOVA test was used for studying inter group variation in different parameters over time. Pearson chi square test and unpaired t-test was applied to analyze differences in categorical and numerical variables respectively. A p value < 0.05 was considered significant. Results: The mean VAS score was less in Group B compared to Group S at all time intervals. VAS score showed greater decline between 1st and 2nd hour in Group B as compared to Group S. No difference was observed in total intra operative dose (in +/-g) of fentanyl (127.5 +/- 12.0 vs. 126.7 +/- 13.0, p> 0.05) and frequency of postoperative analgesic use (3.97 +/- 0.85 vs. 3.93 +/- 0.83, p> 0.05) in Group S vs. Group B respectively. Conclusion: Intraperitoneal bupivacaine provides a simple technique to be used as a part of multimodal approach even though exclusive use of intraperitoneal bupivacaine as a mode of pain relief is not adequate. Use of the correct volume, dose and concentration of drug to bring about this result is of essence.