Minimal flow sevoflurane and isoflurane anaesthesia and impact on renal function.

Goeters C, Reinhardt C, Gronau E, Wüsten R, Prien T, Baum J, Vrana S, Van Aken H

Abstract

BACKGROUND AND AIM: Compound A generation and accumulation in sevoflurane anaesthesia is dependent on fresh gas flow. We investigated the extent of generation of compound A. METHODS: After Institutional Review Board approval and informed consent, patients with normal renal function were randomized to receive either sevoflurane (n = 33) or isoflurane (n = 43) minimal flow anaesthesia (0.5 L min-1) for at least 2 h under standardized conditions. Compound A concentrations were quantified and blood and urine samples were taken to assess renal involvement. Both groups were comparable. RESULTS: No significant differences concerning blood chemistry and urine measurements were found. The maximum mean compound A concentration was observed 90 min after flow reduction being 40 +/- 9 p.p.m. at a corresponding mean sevoflurane concentration of 2.1 +/- 0.5 vol%. Mean inspiratory compound A exposure was 102 +/- 33 p.p.m h-1. CONCLUSION: Compound A concentrations using 0.5 L min-1 fresh gas flow and a heated absorber were higher than previously published values using an inflow of 1 L min-1. Compound A exposure was similar to other clinical studies which did not show changes in renal and hepatic function.