The effect of subcutaneous and intraperitoneal anesthesia on post laparoscopic pain: a randomized controlled trial

A few modes of perioperative local analgesia have been studied in order to reduce postoperative pain after laparoscopy, including preemptive local anesthetics in the trocar sites and intraperitoneal anesthetics administration at the end of the surgery. However, the evidence regarding their efficacy are conflicting. In addition, the combination of both aforementioned methods has been rarely studied. Our aim was to evaluate whether subcutaneous trocar site and/or intraperitoneal analgesia reduce pain after gynecologic operative laparoscopy. This was a single-centered, randomized, controlled, double-blinded trial. The patients were randomly assigned to one of four equally sized groups: group 1—subcutaneous and intraperitoneal analgesia; group 2—subcutaneous analgesia and intraperitoneal placebo; group 3—subcutaneous placebo and intraperitoneal analgesia; Group 4—subcutaneous and intraperitoneal placebo. The patients, the surgeons, and the pain evaluators were all blinded to the patient’s allocation. Included were patients who underwent elective operative laparoscopy. Exclusion criteria were: active infection, pregnancy, known sensitivity to Bupivacaine-Hydrochloride, chronic pelvic pain, surgeries with additional vaginal procedures, conversion to laparotomy, and malignancy. A total of 9 ml of Bupivacaine-Hydrochloride (Marcaine) 0.5%, or Sodium-Chloride 0.9%, as a placebo, were injected subcutaneously to the trocar sites (3 ml to each trocar site), prior to skin incision. In addition, 10 ml of Bupivacaine-Hydrochloride 0.5%, diluted with 40 ml of Sodium-Chloride 0.9% (a total of 50 ml solution), or 50 ml of Sodium-Chloride 0.9%, as a placebo, were injected intraperitoneally at the end of the surgery. By utilizing the 10 cm Visual-analogue-scale (VAS) we assessed post-operative pain at rest at 3, 8, and 24 h, and during ambulation at 8 and 24 h. The study was approved by the local Institutional Review Board and has been registered at clinicaltrials.gov. We conformed to the CONSORT recommendations. Between December 2016 and July 2019, a total of 119 patients were included in the study. Demographic and interventional characteristics were similar among the groups. The level of postoperative pain, either at rest or with change of position, was not significantly different between the groups, at all-time points. Application of subcutaneous and/or intraperitoneal analgesia is not effective in reducing pain after gynecologic operative laparoscopy. Clinical trial identification number: NCT02976571. Date of trial registration 11/29/2016. URL of the registration site: https://clinicaltrials.gov.