Is the amount of carbon dioxide gas used in urologic laparoscopic surgeries associated with postoperative pain?

PURPOSE: We measured how much CO(2) gas was used in urologic laparoscopic surgeries and studied whether the amount of gas was associated with postoperative pain. MATERIALS AND METHODS: Four hundred sixty-three patients underwent urologic laparoscopic surgeries by a single surgeon. All surgeries were performed by a transperitoneal approach under a 15-mm Hg pneumoperitoneum using CO(2) gas. The amount of CO(2) was measured. Neuromuscular blockade with rocuronium was performed during the surgery and patient-controlled analgesia was also applied. Postoperative pain was assessed four times for 24 hours using a 10-point visual analogue scale. RESULTS: The mean laparoscopic time was 75.65±38.19 minutes and the mean amount of CO(2) gas used was 415.70±190.68 L. The mean score on the postoperative pain scale was 6.37±1.48 for 12 hours (sum of measurements taken at 6 and 12 hours after the surgery) and 11.72±2.46 for 24 hours (sum of measurements at 6, 12, 18, and 24 hours). In the statistical analysis, there were no correlations between the amount of CO(2) used and pain scores for 12 and 24 hours postoperatively. There were no correlations between laparoscopic time and pain scores for 12 or 24 hours postoperatively. There were also no correlations between operative method and pain scores for 12 or 24 hours postoperatively. CONCLUSIONS: We recorded the amount of CO(2) gas used for each laparoscopic surgery. There was no correlation between the amount of CO(2) used and postoperative pain. The lack of correlation may have been because the surgery was performed under anesthesia with deep neuromuscular blockade.