Impact of anesthesia technique on post-operative opioid use in open gynecologic surgery in an enhanced recovery after surgery pathway

Objective To examine the effect of anesthesia technique in an enhanced recovery after surgery (ERAS) pathway on post-operative opioid use. Methods Patients undergoing open gynecologic surgery under an ERAS pathway from November 2014 through December 2018 were included retrospectively. All patients received pre-operative analgesia consisting of oral acetaminophen, pregabalin, celecoxib, and tramadol extended release, unless contraindicated. Patients received local wound infiltration with bupivacaine; the post-operative analgesic regimen was standardized. Patients were categorized by anesthesia technique: (1) inhalational, (2) total intravenous anesthesia (TIVA), and (3) combined technique. The primary outcome was post-operative opioid consumption measured as morphine equivalent dose, recorded as the total opioid dose received post-operatively, including doses received through post-operative day 3. Results A total of 1184 patients underwent general anesthesia using either inhalational (386, 33%), TIVA (349, 29%), or combined (449, 38%) techniques. Patients who received combined anesthesia had longer surgery times (p=0.005) and surgical complexity was higher among patients who underwent TIVA (moderate/higher in 76 patients, 38%) compared with those who received inhaled anesthesia (intermediate/higher in 41 patients, 23%) or combined anesthesia (intermediate/higher in 72 patients, 30%). Patients who underwent TIVA anesthesia consumed less post-operative opioids than those managed with inhalational technique (0 (0-46.3) vs 10 (0-72.5), p=0.009) or combined anesthesia (0 (0-46.3) vs 10 (0-87.5), p=0.029). Similarly, patients who underwent the combined technique had similar opioid consumption post-operatively compared with those who received inhalational anesthesia (10 (0-87.5) vs 10 (0-72.5), p=0.34). Conclusions TIVA technique is associated with a decrease in post-operative consumption of opioids after open gynecologic surgery in patients on an ERAS pathway.