Feasibility and Safety Properties of Metabolic-Flow Anesthesia Driven by Automated Gas Control® in Pediatric Patients: A Prospective Observational Study

<i>Background and Objectives</i>: Metabolic-flow (<0.35 L/min) anesthesia is practiced more often as manufacturers provide newer technologies, yet the benefits of metabolic-flow anesthesia have not been fully investigated. This study aimed to investigate the feasibility and safety of automated gas control (AGC^®) mode, which provides metabolic-flow anesthesia, in a pediatric population. <i>Materials and Methods</i>: Pediatric surgery patients between 1 and 10 years of age were included in this prospective observational trial. After intravenous induction and safe orotracheal intubation, AGC^® was initiated, and total sevoflurane consumption (mL) and wash-in speed-based sevoflurane consumption data were collected to measure feasibility. For safety, inspired (F_iO₂), alveolar (F_AO₂), and expired (F_EO₂) oxygen concentration data, and inspired and alveolar sevoflurane (F_iSevo and F_ASevo, respectively) concentration data, were recorded. Changes in fresh gas flow (FGF) throughout the procedure and postoperative recovery data were also compared. <i>Results</i>: A total of 130 patients were eligible for this study, and 121 patients were included in the analyses; 30 patients had a wash-in speed of 4 (WI4) and 91 patients had a wash-in speed of 8 (WI8) at follow-up. The total mean sevoflurane consumption was 9.35 ± 4.93 mL for a median surgery duration of 100 min. WI8 patients consumed more sevoflurane (9.92 ± 5.08 mL vs. 7.79 ± 4.19 mL, <i>p</i> = 0.04). At the 15th and 30th minutes, the FGF dropped under minimal flow and metabolic flow limits, respectively (<i>p</i> < 0.001). The times to extubation and obeying commands were shorter in WI8 patients (8 (5-10) vs. 11 (5-15) <i>p</i> = 0.03, and 9.5 (5-10.5) vs. 13 (9-17) <i>p</i> < 0.01). <i>Conclusions</i>: Maintenance with AGC^® may offer up to 40 h of anesthesia, considering that the volume of a sevoflurane bottle is 250 mL, reflecting exceptional savings compared to conventional anesthesia management. Metabolic flow anesthesia driven by AGC^® is feasible and safe in pediatric anesthesia practice.