Effect of Standardized Pain Treatment in Emergency Abdominal Surgery: A Prospective Observational Cohort Study

Background Optimal pain management strategies following emergency abdominal surgeries remain inadequately defined. This study evaluated the impact of two standardized pain protocols on patients undergoing major abdominal surgery as part of the OMEGA study. Methods This prospective cohort study included patients who underwent major emergency abdominal surgery at a large university hospital in Denmark. Patients were to receive two different multimodal analgesic regimens depending on whether an epidural catheter was possible or not. Data was collected over the first four postoperative days from September 25, 2018, to December 13, 2018. The primary outcome was IV morphine (eqv) consumption on the following individual postoperative days 1- 4 for the cohort with an epidural (COHORT EPI) and the cohort without an epidural (COHORT NO-EPI). Secondary outcomes included pain on the numerical rating scale (NRS), adverse effects, adherence to the protocol, and the extent of sensory coverage provided by the epidural. Results Sixty-six patients were enrolled. Forty-five received pain treatment for COHORT EPI and 21 received pain treatment for COHORT NO-EPI. Epidural anaesthesia was administered to 68% of all patients, most epidurals did not achieve full coverage of the entire surgical wound. The median morphine consumption for the postoperative days 1/2/3/4 for the COHORT EPI was 0/0/0/2 mg, and the COHORT NO-EPI was 15/13/13/12 mg respectively. Despite sub-optimal adherence to the non-opioid analgesic treatment plan, pain was mild at rest and moderate to severe during movement, with infrequent adverse effects for patients for both analgesic plans. Conclusions The implementation of the OMEGA standardized protocol lacked adherence but was accompanied by generally low pain levels at rest and low opioid consumption. These observations may suggest a greater attention towards adherence in the future after implementing a new pain protocol for patients following major abdominal emergency surgery.