Comparison of efficacy of bupivacaine (0.125%) with fentanyl (0.7 mcg/kg) versus morphine (2mg) through epidural for post operative analgesia in total knee arthroplasty.

International association for the study of pain (IASP) defines pain as "An unpleasent sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage".Ineffectively managing pain in the postoperative period often leads to unpleasent consequences like increased cost of care, slower recovery, development of chronic pain.Postoperative pain relief can be achieved by a number of techniques such as intravenous patient controlled analgesia with Opioids,NSAIDS, peripheral local anaesthetics and epidural analgesia. Neuraxial anesthesia includes all the central blocks -  spinal, epidural, and caudal spaces. While it is an invaluable adjunct , it is now even occasionally a good alternative to general anesthesia. Knowledge about the drug used for the epidural block becomes primarily important because it affects duration, desire to have a sensory and/or motor block etc.Epidural administration of local anesthetics and opiates has proven to be effective in the treatment of intra and postoperative pain .Hence, in this sudy we will compare and determine the postoperative analgesic efficacy  of bupivacaine 0.125% with fentanyl 0.7mcg/kg  versus morphine 2mg through epidural in total knee arthroplasty cases.