MULTIDISCIPLINARY PAIN ABSTRACTS: 4 . Anesthesia (4)

Abstract

In this study the authors investigated the duration of labor analgesia produced by a small dose of spinal bupivacaine/fentanyl alone or in combination with a small dose of morphine. Sixty parturients were enrolled in this placebo‐controlled, double‐blinded, randomized trial. All women received a spinal injection of 12.5 μg of fentanyl with 2 mg of bupivacaine. The morphine group (MBF) also received 125 μg of morphine; the placebo group (BF) received saline. Pain scores were <3 of 10 within 10 minutes of the injection. The median duration of analgesia was similar between groups (89 minutes versus 84 minutes), and only 20% of the MBF group experienced prolonged analgesia. During subsequent epidural analgesia, the MBF group had a significantly lesser rate of breakthrough pain (0.15 ± 0.14 episodes per hour versus 0.26 ± 0.18 episodes per hour). Also, during the first 24 hours postpartum, the MBF group required significantly fewer medications (3.3 ± 3.7 doses versus 4.7 ± 3.5 doses). Intrathecal injection of this small dose of bupivacaine/fentanyl produced a rapid onset of labor analgesia; the addition of a small dose of morphine did not significantly prolong analgesia, but it improved subsequent pain relief, as measured by the rate of breakthrough pain and postpartum medication requirements. This may provide a clinically useful means of improving intrapartum and postpartum pain relief. A small dose of intrathecal fentanyl 12.5 μg and bupivacaine 2 mg produces effective labor analgesia lasting for approximately 85 minutes. The addition of a small 125‐ μg dose of morphine improves pain control during subsequent epidural analgesia and reduces the requirements for postpartum pain medications.