Background: We designed this study to investigate the effect of 0.375% ropivacaine on stress hormone responses and anesthetic requirements in combined epidural/general anesthesia for nephrectomy.
Methods: Thirty-two adults, ASA physical status I-II, undergoing nephrectomy lasting about 2 h for renal carcinoma were randomly assigned to one of two groups: epidural (saline)/general anesthesia (group C) and epidural (0.375% ropivacaine)/general (group R) anesthesia. Induction of anesthesia was performed with target-controlled infusion sufentanil and propofol titrated to achieve bispectral index score (define) between 40 and 50. Endotracheal intubation was facilitated by the target-controlled infusion administration of vecuronium. After intubation, anesthesia was maintained with propofol infusion titrated to maintain bispectral index between 40 and 50. The target concentration of sufentanil was titrated according to arterial blood pressure and heart rate. Plasma samples were taken immediately before, 2 min after tracheal intubation, immediately after incision, immediately after the initiation of celiac exploration, 1 h after operation, and immediately after tracheal extubation for measurements of epinephrine, glucose, and cortisol in both groups.
Results: The relative changes of plasma concentrations of glucoses and cortisol were higher at 1 h after operation and immediately after extubation in group C when compared with group R. The plasma concentrations of epinephrine in both groups were similar. The requirements of propofol for induction and maintenance of anesthesia were not statistically different in the groups, but the requirement of sufentanil during maintenance was significant reduced in group R (P < 0.05).
Conclusions: Epidural ropivacaine 0.375% suppressed stress hormone responses and sufentanil requirements perioperatively during maintenance of anesthesia for nephrectomy.