WASHINGTON — Adding epinephrine to epidural bupivacaine and fentanyl significantly reduced the breakthrough pain of women in labor, based on supplemental pain relief data from a randomized study of 107 women with uncomplicated singleton pregnancies.
Previous studies have shown that epinephrine enhances the analgesic effects of local anesthesia during labor, but the effect of epinephrine added during the epidural infusion has not been well studied, noted Dr. Philip E. Hess of Harvard Medical School, Boston.
In this study, Dr. Hess and his colleagues enrolled women in active labor who were at least 7 cm dilated. The average age of the women was 32 years. All the patients received a standard epidural with bupivacaine and fentanyl, and then were randomized to receive or not to receive 1.66 mcg/mL epinephrine (1:600,000) as part of the epidural solution. The results were presented in a poster at the annual meeting of the Society for Obstetric Anesthesia and Perinatology.
“The primary outcome was the need for the treatment of breakthrough pain,” Dr. Hess said during an oral review of posters. Overall, the mean number of boluses of supplemental pain medication was significantly lower in the epinephrine group compared with the control group (1.16 vs. 0.74), and the bolus rate was significantly lower in the epinephrine group compared with the controls.
But there were no significant differences in the duration of labor or in the occurrence of side effects (including hypotension, nausea, and vomiting) between the two groups. Pain scores were recorded every 15 minutes during labor using the visual analog scale. The results suggest that adding epidural epinephrine at the beginning of labor significantly reduced the need for extra anesthesia to manage breakthrough pain, noted Dr. Hess, who said he had no conflicts to disclose.