Purpose: This study examined the sparing effect of sufentanil on the median effective concentration (EC₅₀) of epidural ropivacaine in elderly patients undergoing elective transurethral resection of prostate (TURP).
Materials and methods: This was a prospective randomized double-blind dose-response study. Fifty eight elderly patients with American Society of Anesthesiologists physical status I-II who were scheduled for TURP surgery under epidural anesthesia were randomly allocated to a group receiving 15 mL of ropivacaine (group R) or a group receiving ropivacaine plus 5 μg of sufentanil (group RS). The concentration of ropivacaine was determined by a Dixon's up-and-down sequential allocation. The first participant received 0.3% of ropivacaine in both groups and subsequent concentrations were determined by the response of the previous patient in the same group. The EC₅₀ of epidural ropivacaine was analyzed using the Dixon and Massey method.
Results: The EC₅₀ of ropivacaine during TURP surgery was 0.186% (95% confidence interval, 0.173-0.200%) in group R, and 0.136% (95% confidence interval, 0.127-0.144%) in group RS (p<0.01). No differences in Bromage scale of motor block examination and the onset time of sensory block were observed.
Conclusion: Administration of 5 μg of epidural sufentanil caused a 37% reduction in the EC₅₀ of epidural ropivacaine in elderly patients who underwent TURP surgery. Thus, sufentanil addition during surgery of TURP can decrease the dose of ropivacaine anesthesia required.
Keywords: Ropivacaine; elderly patients; sufentanil.