Association between intraabdominal pressure during gynaecologic laparoscopy and postoperative pain

Laparoscopy is nowadays a well-established surgical method and plays a main role in an ever-increasing range of indications in gynaecology. High-quality studies of surgical techniques are necessary to improve the quality of patient care. The present study aims at evaluating postoperative pain after gynaecological laparoscopy depending on the intraoperative CO₂ pressure.

In a prospective, monocentric, randomized single-blind study at the Department of Gynaecology and Obstetrics at the Hannover Medical School, we include patients scheduled for different laparoscopic procedures. Randomization of the intraoperative CO₂ pressure was carried out in six groups. Pain was assessed the day after surgery by the blinded nurse using a visual analogue scale.

550 patients were included in the period from May 2013 to January 2016. The analysis of the per protocol population PPP (n = 360) showed no statistically significant difference between the six intervention groups with regard to mean postoperative pain perception. In direct comparison between two groups, an intraoperative CO₂ pressure of 15 mmHg was associated with a significant higher pain score than a pressure of 12 mmHg. The difference was 7.46 mm on a 10 cm VAS.

The results of our study indicate that a CO₂ pressure of 12 versus 15 mmHg can be advantageous. However, the clinical relevance remains unclear due to the low difference in pain. The additional benefit of an even lower pressure of 10 or 8 mmHg cannot be reliably assessed; we found signs of poor visibility conditions in these low pressure groups.