Efficacy of intrathecal adenosine for postoperative pain relief

Background and objective: Adenosine, by intravenous and intrathecal routes, is known to alleviate various types of pain. However, the role of intrathecal adenosine in providing postoperative analgesia has not been confirmed. The aim of the present study was to evaluate the efficacy of intrarhecal adenosine for postoperative pain relief, and to determine its role for pre-emptive analgesia. Methods: Ninety ASA I and II females, undergoing elective abdominal hysterectomy, were randomly divided into three groups of 30 patients each. Patients in the 'early adenosine' group received intrathecal adenosine 1000 mu g, 30 min before induction of anaesthesia. Patients in the 'late adenosine' group received the same dose before reversal of neuromuscular blockade. Control patients did not receive any test drug. A balanced general anaesthesia technique was used in all patients. Pain intensity scores using a visual analogue scale, sedation scores, time to first rescue analgesic and total morphine requirement were recorded. Results: There was no significant difference in pain intensity scores, sedation scores, total morphine requirements and time to first rescue analgesic among the three groups. Conclusion: Intrathecal adenosine 1000 mu g is not effective as an analgesic for postoperative pain relief, and there is no pre-emptive effect.