Intraoperative Clonidine for Postoperative Pain Management in Patients Undergoing Surgical Treatment for Endometriosis: a Prospective, Double-blind, Randomized Controlled Trial

Background with aim: Acute postoperative pain is a major and common concern for the large number of patients who undergo surgery each year. Despite advances in pain management strategies, many patients continue to suffer from moderate-to-severe pain during the early postoperative period. This is concerning as unrelieved pain can result in decreased patient satisfaction, increased morbidity, prolonged hospital length-of-stay and increased risk of persistent pain. Effective treatment of acute postoperative pain should therefore be prioritized. Opioid analgesics remain the mainstay treatment for postoperative pain. The potential benefits of opioid therapy for acute pain are short-term pain control. However, there are several potential harms associated with opioid use which may outweigh the benefits including sedation, nausea, vomiting, constipation and risk of long-term use. In this respect, a single dose of clonidine could provide stable analgesia and potentially reduce the need for shorter-acting opioids. Therefore, the investigators decided to carry out the present study with the aim to examine the analgesic efficacy and safety of intraoperatively administered intravenous clonidine in patients undergoing surgical treatment for endometriosis on postoperative opioid consumption, pain intensity and opioid-related side effects.

Method: 120 patients undergoing surgical treatment for endometriosis will be included in this prospective, randomized, double-blind, controlled trial with two arms: an intervention arm (clonidine 150 microgram) and a control arm (isotonic saline). The study will be GCP-monitored, and is approved by the Danish Medicines Agency (2022064017) and the National Committee on Health Research Ethics (2209269).