Comparative study on different routes of intraoperative administration of Ropivacaine to reduce postoperative pain in gynecological laparoscopy - a double blinded randomized trial

Both postoperative pain and side effects of pain therapy result in significant morbidity for patients. Opioids are associated with nausea and respiratory depression, which limit their use in day hospital. For a laparoscopy, local anesthetics can be administered locally by infiltration of the trocar entry points or by instillation in the intraperitoneal cavity. Both methods have proven effective in lowering postoperative pain scores compared to a placebo. This double blinded randomized trial aimed to compare these two local anesthetic techniques, when used either alone or combined in a patient, with respect to postoperative pain scores and the use of rescue pain medication after a gynaecological laparoscopic procedure. Between September 2017 and August 2019, 56 patients (ASA I or 11) who came for a gynaecological laparoscopy in day hospital were enrolled. They were randomly divided into three groups. Group A received both trocar site infiltration and intraperitoneal instillation of Ropivacaine ; group B received intraperitoneal instillation alone and group C received only trocar site infiltration. Further anesthesia and postoperative analgesia were standardized. Following surgery, a questionnaire was completed at 1, 2, 6 and 24 hours and again after 1 week. Pain scores during the first 24 hours and one week after surgery were not significantly different between the three study groups (P-value of 0,55). The use of pain medication, however, was significantly higher in the study group that received both infiltration and instillation of a local anesthetic, compared to the groups who received either instillation or infiltration (P-value of 0,027). This could indicate that a maximal dose of local anesthetics distributed over more than one administration route is less effective in treating pain, than the full dose of 3 mg/kg given in one area. More research is necessary to investigate this possibility.