Background
Reduction of anesthesia cost has become a necessity, especially in developing countries. Recently, automated control of end-tidal sevoflurane concentration (EtSev) has been proposed as a new technique with both cost-effectiveness and safety profiles. In this study, sevoflurane consumption (primary outcome variable) was evaluated during living donor hepatectomy using automated control of EtSev (EtC) at fresh gas flow (FGF) of 0.5 and 2 L/min compared to manual control (MC) technique at FGF of 2 L/min.
Materials and methods
Prospective, randomized, controlled trial including 60 Potential donors scheduled for living donor right hepatectomy. patients were randomized into 3 equal groups (according to target control of sevoflurane), MC group, EtC-2L group, and EtC-0.5L group. In MC group: FGF was set to 2 L/min, inspired concentration of Sevoflurane (FiSev) was set to 1.5–2% in 0.4 fractional inspired oxygen concentration (FiO2), while in EtC-2L group: FGF was set to 2 L/min, EtSev was set to 1–1.5% with end tidal oxygen concentration (EtO2) target of 0.35. In EtC-0.5L group, FGF was set to minimal flow and EtSev target to 1–1.5% and EtO2 target of 0.35. Anesthetic gases consumption (sevoflurane ml, Oxygen L, and air consumption L) per anesthesia hour were recorded at the end of surgery. Other recorded data included intraoperative hemodynamics, the number of user adjustments, and extubation time.
Results
Significant reduction in sevoflurane consumption when EtC-0.5L is used (4.2 ± 1.3 ml/h, 12.6 ± 2.6 ml/h, and 15 ± 2.9 ml/h respectively, . 0.001). Also, a significant decrease in overall numbers of user adjustments between the three groups (8 times for EtC-0.5L group, 7 times in EtC-2L group, 22 times for MC group, . 0.008) was observed.
Conclusion
automated control of EtSev during anesthesia of living donor hepatectomy significantly lowers sevoflurane consumption and decreases required user interventions without deleterious effect on patient safety.