The effect of epidural anesthesia with different concentrations of ropivacaine on sevoflurane requirements.

Abstract

We evaluated sevoflurane requirements during combined general-epidural anesthesia with different concentration of ropivacaine. Fifty-six patients were randomly divided into three groups to epidurally receive saline, 0.2% ropivacaine or 1% ropivacaine. Sevoflurane concentration was adjusted to maintain certain anesthesia depth. BIS values and end-tidal sevoflurane concentrations were recorded at time points of pre-intubation and 5 min, 10 min, 15 min, 20 min, 25 min, 30 min after intubation. End-tidal sevoflurane was significantly lower in the group receiving higher concentration of sevoflurane. Epidural anesthesia can decrease sevoflurane requirements to a larger extent when a higher concentration of ropivacaine was applied.