Opioid have been the main stay to provide analgesia for surgeries. These are however associated with numerous side effects varying from simple delayed recovery to precarious complication like respiratory depression, post operative nausea  vomiting. Opioid sparing maintenance analgesia (OSMA) which include non opioid analgesics has now emerged as a feasible and safe alternative to the conventional opioid based general anaesthesia. The drug most commonly used for non opioid analgesics are dexmedetomidine, ketamine, lignocaine ,MgSO4,dexamethasone and paracetamol. Previous studies have proved that this non opioid analgesics are equally efficacious to opioid and can be alternative to opioids. In previous studies, those used either single drug infusion or combination drug (for example., ketamine and dexmedetomidine)  showed they are equally efficacious to fentanyl and can be used as an alternative to opioid. But there is no study comparing the combination of non opioid analgesics. So we thought to conduct a study comparing the combination of non opioid analgesics under entropy guided monitoring. We will divide all the recruited patient into three groups keto-dex, keto-lig and control groups. For keto-dex group(ketamine:0.2mg/kg/hours+ dexmedetomidine :0.5 microgram/kg/hour) and for keto-lig group (ketamine:0.2mg/kg/hour + lignocaine: 1 mg/kg/hour) and for control group normal saline infusion will be started immediately after  intubation for maintenance analgesia in intraoperative period with entropy monitoring. Extra doses of fentanyl (0.5mcg/kg) bolus will be given to every patients under entropy guided monitoring and if the difference between response entropy(RE )and state entropy(SE) exceed more than 10 and will be noted in every patients in all group.   In the postoperative period rescue analgesia will be done by fentanyl and noted. In the postoperative period assessment of pain will be done by VAS, recovery by modified Aldrete’s score, sedation by Ramsay sedation score.