Comparison of clinical effects according to dosage of fentanyl added to 0.5% hyperbaric bupivacaine for spinal anesthesia in patients undergoing cesarean section

ABSTRACT

BACKGROUND: Spinal anesthesia for cesarean section is widely used technique for rapid induction, high success rate and excellent intraoperative and postoperative analgesia. Potentiating the effect of intrathecal local anesthetics by addition of opioid for cesarean section is well known. In this study, we compared the clinical effects when different doses of fentanyl were combined with intrathecal hyperbaric bupivacaine. METHODS: Ninety six healthy term parturients were randomly divided into four groups Group C (control), Group F10 (fentanyl 10 microg), Group F15 (fentanyl 15 microg), F Group F20 (fentanyl 20 microg). In every group, 0.5% heavy bupivacaine was added according to the adjusted dose regimen. We observed the maximal level of the sensory block and motor block, the quality of intraoperative analgesia, the duration of effective analgesia and the side effects. RESULTS: There were no significant differences between four groups in maximal level and recovery rate of sensory and motor block. Quality of intraopertive analgesia and muscle relaxation was increasing by increasing dosage of intrathecal opioids. Duration of effective analgesia was significantly prolonged in Group F15 and F20 than Group C and F10, but there were no differences between Group F15 and F20. And the frequencies of side effects such as hypotension, max sedation level were increasing by increasing dosage of intrathecal opioids. The Apgar scores were normal, and there were no differences between the four groups. CONCLUSIONS: The addition of fentanyl 15 microg for spinal anesthesia provides adequate intraoperative analgesia and good postoperative analgesia without significant adverse effects.