Comparison of intrathecal bupivacaine-fentanyl and bupivacaine-butorphanol combinations for joint replacement surgeries

BACKGROUND AND AIMS: The objective of the study was to compare duration of analgesia of fentanyl versus butorphanol as adjuvants to bupivacaine in spinal anesthesia. MATERIAL AND METHODS: A prospective, randomized, double-blinded study conducted in 80 patients of 18–75 years age group and American Society of Anesthesiologists Grades I and II undergoing joint replacement surgeries. A total of 40 patients in each Group A and Group B received 0.5% bupivacaine 3 ml with 25 mcg fentanyl and 25 mcg butorphanol respectively, in a total volume of 3.5 ml made with saline. Duration of analgesia, number of rescue analgesia, sensory, and motor block characteristics were compared between the two groups. Statistical analysis was done using t test and Chi-square test with SPSS 19.0 software. RESULTS: Mean duration of analgesia was found more in Group B in comparison to Group A (P < 0.05). A number of doses of analgesic required postoperatively were more in Group A compared to Group B (P < 0.001). Time required for onset of sensory and motor block was comparable in both the groups. However, two segment regression of sensory block was slower in Group B compared to Group A (P < 0.05). CONCLUSION: We conclude that addition of butorphanol 25 μg as an adjuvant to 0.5% hyperbaric bupivacaine provided prolonged duration of analgesia compared to 25 mg fentanyl.