Spinal Anesthesia 0.75% Isobaric Ropivacaine with Fentanyl for a Lower Extremity Operation

Abstract

Background: Opioids and local anesthetics administered together intrathecally have a potent synergistic analgesic effect and less hypotention using a minidose of local anesthetic. This study was designed to investigate the safety and efficacy of two doses of intrathecal isobaric ropivacaine/fentanyl in patients undergoing an operation of the lower extremities. Methods: Thirty patients undergoing an elective orthopedic surgical operation of the lower extremities were randomly assigned to two groups for spinal anesthesia. Patients in group I (n = 15) received 0.75% ropivacaine 14 mg/fentanyl 20, and patients in group II (n = 15) received 0.75% ropivacaine 16 mg/fentanyl 20. After spinal anesthesia, we measured the time to T10, peak dermatomal level, time to peak sensory level, time to maximum motor blockade, duration of complete motor block and duration of complete sensory block using the pin prick test and Bromage motor scale. Also circulatory variables were monitored every 5 min and side effects were measured for 3 days after spinal anesthesia. Results: There were no significant differences between the groups in time to T10, peak dermatomal level, time to peak sensory level, time to maximum motor blockade and duration of complete motor block, but duration of complete sensory block was significantly longer in the 0.75% ropivacaine 16 mg/fentanyl 20 group than the 0.75% ropivacaine 14 mg/fentanyl 20 group. Conclusions: Intrathecal 0.75% ropivacaine 14 mg/fentanyl and 0.75% ropivacaine 16 mg/fentanyl were equally suitable for a lower extremity operation.