Nitrous oxide anesthetic versus total intravenous anesthesia for functional endoscopic sinus surgery

Background: Functional endoscopic sinus surgery is a common procedure for sinonasal disease, frequently performed in the outpatient setting. General anesthesia maintained with total intravenous anesthesia (TIVA) with propofol has been shown to give superior surgical conditions compared to inhaled anesthetics. This study evaluated the effects of TIVA versus a predominantly nitrous oxide (N₂O)–based anesthetic with a low-dose propofol and remifentanil infusion on sinus surgery. Methods: Patients were randomized to either a N₂O-based (nitrous oxide with propofol and remifentanil) or TIVA (propofol and remifentanil without nitrous oxide) group. The surgeon was blinded to the anesthetic technique. Surgical field grading was performed in real time by the otolaryngologist every 15 minutes with the Boezaart grading system. Results: There were no statistically significant differences between the Boezaart scores, duration of surgery, or estimated blood loss between the two anesthetic techniques. However, the use of N₂O provided a statistically significant, 38% reduction in time from surgery end to extubation. The TIVA group had significantly decreased mean and median pain scores in the post-anesthesia care unit (PACU). There was no difference in the rate of postoperative nausea and vomiting between the two groups. Conclusion: A N₂O-based anesthetic for functional endoscopic sinus surgery provides similar intraoperative and postoperative conditions when compared to TIVA, while being superior in terms of time to extubation. Although the TIVA group had significantly decreased pain scores, this did not lead to a decrease in pain medicine received in the PACU, and there was no difference between groups in time to discharge. Level of Evidence: 1b. Laryngoscope, 130:E299–E304, 2020.