Intrathecal labor analgesia with bupivacaine and sufentanil: The effect ofadding 2.25 mu g epinephrine

Background and objectives: Epinephrine, 25 mug and 200 mug, has been found to prolong the duration of intrathecal labor analgesia when added to an opi oid. In our hospital we use the standard epidural mixture, prepared by the pharmacist, containing epinephrine 1:800,000; i.e., 1.25 mug/mL for both sp inal and epidural labor analgesia. We wanted to evaluate whether such a low dose, depending on its effect on duration or quality of analgesia, should be maintained or deleted in future mixtures. Methods: Forty-five term parturients were randomly assigned to receive 1.8 mL intrathecally of a mixture containing bupivacaine 0.125% and sufentanil 0.75 mug/mL with or without epinephrine 1.25 mug/mL. The quality and durati on of analgesia, side effects, and obstetric/neonatal outcome were compared . Results: For both combinations, the onset until the first painless contract ion was between 5 and 6 minutes. Most patients were pain free during the se cond uterine contraction. The duration of complete analgesia was 93.2 +/- 2 4.2 minutes in the epinephrine group and 79.3 +/- 18.1 minutes for patients not receiving epinephrine (P = .014). The quality of the block, bupivacain e consumption, side effects, and obstetric/neonatal outcome were not differ ent between groups. Conclusions: It was concluded that epinephrine in a dose as low as 2.25 mug significantly prolonged the duration of intrathecal analgesia of bupivacai ne-sufentanil by 15 minutes. No other differences were noticed. Diluting th e commercially available bupivacaine 0.5% with epinephrine 1:200,000 may av oid the need of freshly prepared epinephrine solutions.