Addition of dextrose 3.5% to intrathecal sufentanil for labour analgesia reduces pruritus

Purpose: To determine whether the addition of a low concentration (3.5%) of dextrose would minimize pruritus while maintaining the quality of analgesi a. Methods: In a double blind study 48 parturients in early labour were random ized to one of two study groups: dextrose (Dex, n = 24; 10 mug sufentanil i n dextrose 3.5%), or normal saline (NS, n = 24; 10 mug sufentanil in normal saline). Parturients received the study drug as the intrathecal injection of the combined spinal-epidural (CSE) technique for labour analgesia. Durat ion and degree of analgesia were measured until epidural analgesia was init iated or delivery of the baby. The intensity and distribution (above T-6, T -6-L-1, and below L-1) of pruritus were measured at five minute intervals d uring first 25 min after injection. Results: Quality and duration of analgesia did not differ between groups, b ut the overall incidence of pruritus was less in the Dex group (88% vs 42%, P = 0.001). Within each region, the incidence of pruritus was less in the Dex group. In patients who had pruritus, for the Dex group, the incidence o f pruritus in the upper region (>T6) was lower than the NS group. There was no difference in the lower regions. Conclusion: The addition of dextrose 3.5% to intrathecal sufentanil reduced the incidence of pruritus without affecting the duration or quality of ana lgesia in parturients in early labour. The distribution of pruritus in the Dex group was limited to below T-6 suggesting that pruritus to intrathecal sufentanil is mediated at the spinal level.