Comparison of two sevoflurane formulations in low-flow anesthesia: a retrospective observational study

Background This study aimed to compare two different sevoflurane formulations (Sevones® and Sevorane®) under low-flow anesthesia in terms of time to 1 Minimum Alveolar Concentration (MAC), agent consumption and uptake, emergence profile, and anesthesia-related complications. Methods This retrospective observational study was conducted at Sakarya University Training and Research Hospital, Türkiye. A total of 89 female patients undergoing elective gynecologic surgery under general anesthesia with low-flow sevoflurane (≤ 1 L/min) were included. Patients received either Sevones® (n = 46) or Sevorane® (n = 43). Standardized anesthetic induction with propofol and rocuronium was followed by low-flow sevoflurane maintenance. The primary outcome was time to reach 1 MAC. Secondary outcomes included agent consumption and uptake during induction and maintenance, emergence characteristics, intraoperative hemodynamic and PSI trends, and anesthesia-related complications. Statistical comparisons were performed using t-test, Mann–Whitney U, and chi-square tests as appropriate. Results Time to reach 1 MAC was similar between Sevones® and Sevorane® groups (198.26 ± 41.1 s vs. 205.63 ± 51.2 s; p = 0.455). Agent consumption and uptake during induction were comparable. Total agent uptake was significantly higher in the Sevones® group (16.63 ± 5.32 mL vs. 13.49 ± 7.45 mL; p = 0.024), while total agent consumption showed no significant difference. Emergence times, PSI trends, and complication rates were similar between groups. Conclusions Both Sevones® and Sevorane® demonstrated comparable pharmacokinetic and pharmacodynamic profiles under low-flow anesthesia. The findings support their safe and effective use during elective gynecologic surgery. Clinical trial number Not applicable.