Intraperitoneal gas drain to reduce pain after laparoscopy: randomized masked trial

To determine whether a drain placed in the peritoneal cavity during laparoscopy is both a clinical and cost-effective method of reducing postoperative pain.

Two hundred twenty-five women undergoing diagnostic or minor operative laparoscopic procedures were recruited. Women were assigned to receive either an intraperitoneal gas drain or a dummy drain during surgery. Sample size to detect a two-point difference in visual analogue score was estimated at 158 subjects, with 79 in each arm. The patients and nursing staff were unaware of the position of the drain. A visual analogue score was used to assess pain preoperatively and at 4, 24, and 48 hours postoperatively. Data on the experience of nausea, frequency of vomiting, and site of pain were collected. The analgesic and antiemetic use was recorded. An economic evaluation of the analgesic use and the material costs for the two groups was performed.

One hundred sixty-one complete sets of data (72%) were available for analysis. The two groups were well matched for age, parity, previous surgery, body mass index, volume of carbon dioxide used, and operative time. No significant differences were found between the two groups with regard to the overall pain scores preoperatively (8 versus 7) or at 4 (30 versus 34), 24 (40 versus 44), and 48 (26 versus 26) hours postoperatively, after adjusting for multiple point testing. On assessment at different sites, the dummy drain group experienced shoulder pain more frequently at 4 (19 of 79 versus 10 of 82, P =.05) and 48 (16 of 79 versus 7 of 82, P =.03) hours postoperatively compared with the drain group. The placebo group had a 33% greater usage of oral analgesia after discharge, but this was $2.50 cheaper than the use of an intraperitoneal drain. No statistically significant differences were found between the groups with regard to nausea and vomiting postoperatively.

An intraperitoneal drain after minor gynecologic laparoscopy decreases the frequency of shoulder pain and reduces postoperative analgesia requirements. However, it is less cost-effective to reduce pain using an intraperitoneal gas drain than simple oral analgesia after minor gynecologic laparoscopy.