Addition of adenosine to hyperbaric bupivacaine in spinal anaesthesia does not prolong postoperative analgesia in vaginal hysterectomy

Abstract

Background: Systemic administration of adenosine produces anti-nociception. Although literature supports intrathecal adenosine for neuropathic pain, its efficacy in postoperative pain remains unproven. There has been no study on the efficacy of adenosine on postoperative pain when administered with hyperbaric bupivacaine. The aim of our present study was to evaluate the efficacy of two different doses of intrathecal adenosine as an adjunct to 0.5% hyperbaric bupivacaine in patients undergoing vaginal hysterectomy under spinal anaesthesia. Method: Seventy-five women, aged 40-60 years and scheduled for vaginal hysterectomy under spinal anaesthesia, were included. Patients were allocated to three groups of 25 patients each to receive 500 μg adenosine (group I), 1000 μg adenosine (group II) and normal saline (group III) with 2.6 ml of 0.5% hyperbaric bupivacaine. Postoperative analgesia was provided with patient-controlled fentanyl. Time of administration of rescue analgesia and total dose of fentanyl were recorded. The times to full recovery of sensory and motor block were noted. Results: There were no differences in time to rescue analgesia and postoperative fentanyl consumption over 24 hours among the groups. There was no significant difference in onset of sensory and motor block or regression of sensory block, although statistically significant difference was noted in the time taken for regression of motor block. Conclusion: Intrathecal adenosine does not affect the postoperative analgesic requirement when administered with hyperbaric bupivacaine.

Keywords: spinal anaesthesia, intrathecal adenosine, vaginal hysterectomy,
postoperative analgesia, patient-controlled analgesia