Pain Relief in Laparoscopic Surgery

Pain after laparoscopic surgery remains an important concern in the treatment of endometriosis or other gynaecologic laparoscopic surgery. Several trials have demonstrated that the use of an altered insufflation gas (10 % nitrous oxide + 4% oxygen + 86% carbon dioxide) reduces pain. It also decreases inflammation and adhesion formation as a surplus. With this mono-center, investigator initiated, double-blinded, randomized controlled superiority trial, the investigators want to demonstrate a reduced postoperative pain and peritoneal inflammatory reaction following peritoneal conditioning with an altered insufflation gas compared to the standard carbon dioxide (100% CO2) insufflation gas. Therefore, women undergoing laparoscopic (gynaecological) surgery with an estimated surgical time of \>60 minutes will be asked to participate in this trial. Baseline characteristics will be assessed, including the patients' age, body mass index, medial history, American Society of Anesthesiologist Classification (ASA classification), work status, highest level of education, fear for the surgical procedure (using an 8-item surgical fear questionnaire), pre-operative pain (using a Numerical Rating Scale (NRS) were 0= no pain and 10= worst pain imaginable) both in resting position and in an active position), expected pain (NRS), baseline quality of recovery (QOR) (using the 1-item Global Surgical Recovery (GSR) index (3) and the Functional Recovery Index (FRI) (4)) as well as baseline quality of Life (QOL), using the 5-dimensional European Quality of Life (EQ-5D) questionnaire.