The effects of morphine and fentanyl alone or in combination added to intrathecal bupivacaine in spinal anesthesia for Cesarean section

Abstract

Objectives: This randomised double-blind controlled trial examines the effects of fentanyl and morphine, alone and in combination, as adjuncts to spinal anesthesia for elective Cesarean section.
Methods: Sixty women undergoing elective Cesarean section, with spinal anesthesia using 0.5% hyperbaric bupivacaine were randomly allocated to receive morphine 0.2 mg, fentanyl 25 μg, or fentanyl 12.5 μg plus morphine 0.1 mg, intrathecally. The start of spinal block, the time to T10 level, the highest sensorial and motor block level, time to regresion of sensory block to T10, the time to resolution of motor block, surgical characteristics, maternal side-effects, Apar and NACS scores, umbilical blood gas evaluations, time to first analgesic requirement were recorded.
Results: There was no patient having pain during the intraoperative period. The degree and time of sensorial and motor block was similar in both groups and there was no difference in the time to T10 level and the time to reversal of motor block. The difference in time to first postoperative analgesic requirement was statistically significant. There was no difference between groups in postoperative side effects. There was no neonatal difference in Apgar, NACS and umbilical blood gas evaluations.
Conclusions: The quality of postoperative analgesia with morphine, when used alone, was found to be superior to that with fentanyl. The combination of opioids offered no advantages over morphine alone.