Background and Objectives Despite growing popularity, there are few studies examining the relative efficacy of different doses of intrathecal sufentanil for labor analgesia. This prospective, randomized, double-blind study compared the efficacy and side effects of 5 and 10 μg intrathecal sufentanil.

Methods Sixty-three healthy, laboring, term parturients ≤5 cm cervical dilation participated in this study. In a randomized, double-blind fashion, patients received 5 or 10 μg intrathecal sufentanil as part of a combined spinal epidural technique. Patients rated pain, itching, nausea, and sedation on verbal analog scales before and every 10 minutes after drug injection. We also recorded maternal blood pressure and peripheral oxygen saturation before and every 10 minutes after drug injection. Before and 30 and 60 minutes after drug injection, we measured maternal end-tidal CO₂.

Results Both doses of sufentanil provided adequate analgesia. Although 10 μg sufentanil produced slightly more profound analgesia, the duration of pain relief did not differ between the two groups. Both drug doses were associated with significant increases in itching and end-tidal CO₂. The 10-μg dose was associated with more sedation and a greater decrease in SaO₂.

Conclusions Both 5 and 10 μg intrathecal sufentanil provided adequate labor analgesia. Both doses were associated with measurable spinal (itching) and supraspinal (sedation, respiratory depression) side effects.