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.