Background: End-stage renal disease (ESRD) has been shown to be associated with abnormal neural function. Clinically used inhaled anesthetic agents typically exert their effect through multiple target receptors in the central nervous system. Pathological changes in the brain may alter sensitivity to inhaled anesthetic agents. This study aimed to determine the minimum alveolar concentration-awake (MACawake) of sevoflurane in patients with ESRD compared to patients with normal renal function.
Methods: Patients underwent inhalational induction of anesthesia and received sevoflurane at a preselected concentration according to a modified Dixon "up-and-down" method starting at 1.0% with a step size of 0.2%. The concentration of sevoflurane used for each consecutive patient was increased or decreased based on a positive or negative response to verbal command in the previous patient. Serum neuron-specific enolase, a biomarker of impaired neurons, was also measured.
Results: Forty-one patients were enrolled: 20 with ESRD and 21 as controls. The MACawake of sevoflurane in patients with ESRD was significantly lower than that observed in the control group (0.56% [standard deviation {SD} = 0.10%] vs 0.67% [SD = 0.08%]; P = .031). Patients with ESRD exhibited higher serum neuron-specific enolase levels compared to the control group (16.4 ng/mL [SD = 5.0] vs 8.7 ng/mL [SD = 2.9]; P < .001).
Conclusions: MACawake of sevoflurane is somewhat lower in patients with ESRD compared to those with normal renal function. Impaired cerebral function may partly contribute to the reduction in anesthetic requirement.