The economic evaluation of nitrous oxide in sevoflurane anesthesia

ABSTRACT

BACKGROUND: Nitrous oxide (N2O) is much cheaper than recently introduced volatile anesthetics such as sevoflurane and desflurane, and can reduce the consumption of these anesthetics. The use of N₂O is under current debate. The purpose of this study was to evaluate economic effect of 50% N₂O during sevoflurane anesthesia in Korea. METHODS: Seventy patients were randomly allocated to Group A or Group N. Anesthesia induction was performed using propofol, rocuronium, and 3–5% of sevoflurane with air (Group A) or 50% N2O (Group N). Fresh gas flow (FGF) was 6 L/min during induction, and 3 L/min for maintenance. Mean arterial pressure (MAP), heart rate (HR), bispectral index (BIS), and minimum alveolar concentration (MAC) were recorded. The consumption of sevoflurane was measured at every 10 minutes for the first 1 hour. The economic effect was analyzed based on the payment criterion of Korean National Health Insurance Service. RESULTS: MAP, HR, BIS, and MAC showed no differences between the two groups. The sevoflurane consumptions for the first 1 hour were 39.2 ± 6.3 ml in Group A and 29.2 ± 4.9 ml in Group N (P < 0.01); and the N₂O consumption was 93.7 ± 1.5 L in Group N. The total costs of inhaled anesthetics were 16,190 (14.8 USD) and 13,062 (12.0 USD) Korean won for the first 1 hour in Groups A and N, respectively. CONCLUSIONS: Use of 50% N₂O with 3 L/min FGF reduced the sevoflurane consumption by 25% and anesthetic cost by 20% for the first 1 hour.