Onset of Labour Epidural Analgesia With Different Concentration Bupivacaine and Different Doses of Sufentanyl

Epidural block is widely used as an analgesic method during labor. During epidural anaesthesia, lipophilic opioids such as sufentanil, are often combined with local anesthetics to prolong the duration of analgesia and improve the analgesic effect. However, dose combinations of local anesthetics and opioids, especially in the initial loading dose, vary greatly from hospital to hospital and often depend upon the different routines adopted by anesthesiologists. In clinical practice, there are still some controversy about opioid dose selection in terms of analgesic onset time and adverse reactions.

In this study, three combinations of bupivacaine and sufentanil were chosen, commonly used in the clinic, and extended the observation period to 24 hours after delivery. We hypothesized that increasing the concentration of local anesthetic, rather than increasing the dose of sufentanil, would achieve a faster analgesic effect with minimal adverse effects on the mother and fetus. To test our hypothesis, our primary outcome was to compare the times of analgesia onset of the three combinations, and the secondary outcomes were to compare the effects on maternal and infant adverse reactions.