Perioperative analgesia with subarachnoid fentanyl-bupivacaine for cesarean delivery

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 micrograms fentanyl 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 greater than or equal to 6.25 micrograms fentanyl required intraoperative opioids. Complete analgesia (time from injection to first report of pain) lasted 33.7 +/- 30.8 min (mean +/- SD) in the control group and increased to 130 +/- 30 min (P less than 0.05) with addition of 6.25 micrograms 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 less than 0.05) to 192 +/- 74.9 min with addition of 6.25 micrograms fentanyl.(ABSTRACT TRUNCATED AT 250 WORDS)