Lessons from the Analysis of a Retrospective Cohort of Patients Who Underwent Large Open Abdominal Surgery Under Total Intravenous Opioid-Free Anesthesia

Background Opioid-free anesthesia (OFA) is a new method of anesthesia based on a paradigm shift. Under general anesthesia, the physiology and/or the pathophysiological variations clinically observed are more a reflection of a systemic reaction to the stress (surgical and anesthesia stresses) than a true reflection of pain. Objective To report the results of a large monocenter, retrospective, non-interventional observational study of all consecutive patients who received a total intravenous (IV)-OFA protocol for the surgical management of major open abdominal and urological surgery. Patients and Methods We retrospectively extracted the anesthesia files of 311 consecutive patients (regional anesthesia excluded). No opioids were administered to any of these patients during the surgery. IV morphine administered in the recovery room was the primary endpoint of the study. The secondary endpoints included the amount of opioid required during the first two postoperative days, as well as the maximum pain intensity. Results Only very small doses of IV morphine were administered. The mean total morphine titration was 2 mg (1.9 ± 2.9 mg), corresponding to control of the maximal level of pain to 2.1 ± 2.6 as evaluated with a numerical scale in the postoperative care unit. Similarly, we observed a very low level of morphine consumption during the first two postoperative days. Conclusions These results highlight the safety and the feasibility of our total IV-OFA protocol, thus confirming this new paradigm. Under general anesthesia, the cardiovascular and inflammatory response to the stress could be reliably managed through a multimodal approach without a need for opioids. In the postoperative period, very low doses of opioids were required.