The effect of peritoneal gas drain on postoperative pain in benign gynecologic laparoscopic surgery: a double-blinded randomized controlled trial.

OBJECTIVES: To compare the effect of peritoneal gas drain on postoperative pain in benign gynecologic laparoscopic surgery and the amount of postoperative analgesic dosage.

METHODS: The trial included 45 females who had undergone operations during the period December 2014 to October 2015. The patients were block randomized based on operating time (<2 and ≥2 hours). The intervention group (n=23) was treated with postoperative intraperitoneal gas drain and the control group (n=22) was not. The mean difference in scores for shoulder, epigastric, suprapubic, and overall pain at 6, 24, 48 hours postoperatively were statistically evaluated using mixed-effect restricted maximum likelihood regression. The differences in the analgesic drug usage between the groups were also analyzed using a Student's t-test. The data were divided and analyzed to two subgroups based on operating time (<2 hours, n=20; and $2 hours, n=25).

RESULTS: The intervention had significantly lower overall pain than the control group, with a mean difference and 95% confidence interval at 6, 24, and 48 hours of 2.59 (1.49-3.69), 2.23 (1.13-3.34), and 1.48 (0.3-2.58), respectively. Correspondingly, analgesic drug dosage was significantly lower in the intervention group (3.52±1.47 mg vs 5.72±2.43 mg, P<0.001). The three largest mean differences in patients with operating times of ≥2 hours were in overall pain, suprapubic pain at 6 hours, and shoulder pain at 24 hours at 3.27 (1.14-5.39), 3.20 (1.11-5.26), and 3.13 (1.00-5.24), respectively. These were greater than the three largest mean differences in the group with operating times of <2 hours, which were 2.81 (1.31-4.29), 2.63 (0.51-4.73), and 2.02 (0.68-3.36). The greatest analgesic drug requirement was in the control group with a longer operative time.

CONCLUSION: The use of intraperitoneal gas drain was shown to reduce overall postoperative pain in benign gynecologic laparoscopic surgery. The effects were higher in patients who had experienced longer operating times.