Epidural analgesia is a simple and safe technique that produces effective block with small dose of local anaesthetic. It provides extended post-operative pain control that is superior to that provided by systemic opioids alone. Thoracic epidural analgesia (TEA) provides good postoperative pain relief and facilitates deep breathing exercises and early ambulation. Sympathetic outflow decreases with use of TEA. To achieve desired post-op analgesic effect, invariably large volumes of local anaesthetics are used, thereby increasing the possibilities of local anaesthetic toxicity and deleterious hemodynamic consequences. Opioids like fentanyl have been used traditionally as an adjunct for epidural administration in combination with a lower dose of local anaesthetic to achieve the desired analgesic effect. The addition of opioid does provide a dose sparing effect of local anaesthetic and superior analgesia but there is always a possibility of an increased incidence of nausea, vomiting and respiratory depression. 

Dexmedetomidine is an alpha-2 agonist which has got numerous beneficial effects. It acts on both pre and post synaptic sympathetic nerve terminal and central nervous system thereby decreasing the sympathetic outflow and nor-epinephrine release. Dexmedetomidine has an effective sedative, anti-anxiety and analgesic effect. Dexmedetomidine does cause a manageable hypotension and bradycardia but it does not cause opioid related side effects like respiratory depression, nausea and vomiting.

Therefore, we planned to compare the post operative analgesic efficacy of dexmedetomidine vs fentanyl as an adjuvant to bupivacaine in thoracic epidural for midline laparotomies.