Addition of fentanyl to bupivacaine administered for spinal anesthesia for cesarean delivery was evaluated in 56 ASA physical status 1 term parturients. Preservative-free saline was added to 0, 2.5, 5, 6.25, 12.5, 25, 37.5, or 50 [mu]g featanyl to make a 1 ml total volume, which was injected intrathecally prior to bupivacaine in a double-blind, randomized fashion. Vital signs, sensory level, motor block, pain score, and side effects were recorded every 2 min for the first 12 min and then at 15, 30, 45, and 60 min and at 30-min intervals until the patient complained of pain. At delivery maternal vein, umbilical artery, and umbilical vein blood gases were obtained. Apgar scores at 1 and 5 min were recorded. Early Neonatal Neurobehavioral Scales (ENNS) were performed on days 1 and 2. Side effects and opioid requirements were recorded for the first 24 h. All of the patients in the control group reported a pain score greater than 0 during surgery and 67% required intraoperative opioids. None of the patients who received >=6.25 [mu]g fentanyl required intraoperative opioids. Complete analgesia (time from injection to first report of pain) lasted 33.7 +/- 30.8 min (mean [middle dot] SD) in the control group and increased to 130 +/- 30 min (P < 0.05) with addition of 6.25 [mu]g fentanyl. Duration of effective analgesia (time from injection to first parenteral opioid) was 71.8 +/- 43.2 min in the control group and increased (P < 6.05) to 192 +/- 74.9 min with addition of 6.25 [mu]g fentanyl. Increasing the doses of fentanyl above 6.25 [mu]g did not further increase duration of complete or effective analgesia. Twenty-four-hour opioidic requirements were not affected by addition of fentanyl. UV and UA blood gases were within normal limits. No differences were found between groups in Apgar scores or ENNS. Results indicate that the addition of 6.25 [mu]g fentanyl to hyperbaric bupivacaine for spinal anesthesia improves intraoperative analgesia and provides analgesia into the immediate postoperative period with no adverse effects on mother or neonate.
(C) 1989 American Society of Anesthesiologists, Inc.