RESUMO
BACKGROUND: Anesthetists participating in laparoscopic cholecystectomy (LC) with CO2 pneumoperitoneum has been cautious about adapting low-flow anesthesia (LFA). We investigated the efficacy of LFA compared to high-flow anesthesia (HFA) in LC. METHODS: Eighty patients undergoing LC were randomly assigned to one of the two groups (n = 40 each). In LFA, 1 L/min (50% O2 and N2O) of the total fresh gas flow (FGF) was used, whereas 4 L/min of the total FGF was used for HFA. Inspiratory and expiratory concentrations of O2, N2O, CO2, and sevoflurane were serially measured. Subjects were monitored for heart rate, blood pressure, and any procedural complications. RESULTS: None of the patients experienced any episodes of hypoxia, hypercapnia, and arrhythmia in both groups. The maximal end-tidal CO2 was 40.9 +/- 3.9 mmHg in LFA and 38.2 +/- 3.6 mmHg in HFA, respectively. The minimal O2 saturation was 98.3 +/- 0.6% in LFA and 98.8 +/- 0.7% in HFA, respectively. The inspiratory CO2 concentrations in both groups were all less than 1 mmHg throughout the anesthesia. CONCLUSIONS: In conclusion, LFA with sevoflurane using FGF of 1 L/min with setting of 50% O2 and N2O for LC could be performed safely without the risk of complications like hypercapnia, hypoxia, or arrhythmia compared to HFA.