Maternal and neonatal effects of adding morphine to low‑dose bupivacaine for epidural labor analgesia
Aim: Labor is one of the most painful experiences a woman may face during her lifetime. One of the most effective methods used for eliminating this pain is epidural analgesia. The aim of this study to determine the impact of adding morphine to low‑dose bupivacaine epidural anesthesia on labor and neonatal outcomes, and maternal side effects.
Materials and Methods: This is a prospective randomized double‑blind study comparing two regimens of anesthetic agents used for epidural anesthesia in labor. A total of 120 pregnant women were randomized into two groups with 60 subjects in each study arm. A catheter was inserted, and 0.1% bupivacaine + 2 μg/mL fentanyl in 15 mL saline were given to Group bupivacaine‑fentanyl (Group BF), while 0.0625% bupivacaine + 2 μg/ml fentanyl + 2 mg morphine in 15 mL saline were given to Group bupivacaine‑fentanyl‑morphine (Group BFM) with no test dosing from the needle. No morphine was added to the subsequent epidural injections in Group BFM.
Results: The total dose of bupivacaine was significantly lower in Group BFM relative to Group BF (P = 0.0001). The visual analogu scalescores at 15, 30, and 45 min were significantly lower in Group BF compared to thosein Group BFM (P = 0.0001, P = 0.001, and P = 0.006, respectively). The second stage of labor was significantly shorter in Group BFM relative to Group BF (P = 0.027 and P = 0.003, respectively). The satisfaction with analgesia following the first dose was higher in the nonmorphine group (P = 0.0001). However, maternal postpartum satisfaction was similar in both groups. Either nausea or vomiting was recorded in eight patients in Group BFM.
Conclusion: We believe that epidural analgesia comprised of a low‑dose local anaesthetic and 2 mg morphine provides a painless labor that significantly reducesthe use of local anesthetic without changing the efficiency of the analgesic, ensuring the mother’s satisfaction without leading to an adverse effect on the mother or foetus, while mildly (but significantly) shortening the second stage of labor.
Key words: Bupivacaine, epidural analgesia, fentanyl, morphine, painless labor