The Effect of Anaesthetic Drugs on Recovery in Patients Undergoing Cancer surgery

Intervention1: KETAMINE: Patients will be randomised to receive low dose ketamine infusions @ 0.1 mg/kg/hr + GA + Epidural; ketamine infusion will be started around the time of skin incision Intervention2: DEXMEDETOMIDINE: : Dexmedetomidine IV infusions @ 0.25 mcg/kg/hr + GA + Epidural; dexmedetomidine infusion will be started around the time of skin incision around the time of incision Control Intervention1: NORMAL SALINE: 0.9 % Saline IV infusions @ 5 ml/hr Primary outcome(s): 1.To assess the effect of infusion of a low dose of ketamine and dexmedetomidine infusions vs placebo on the time to passage of flatus in patients undergoing GI malignancy surgeries.Timepoint: Post - Operatively 24 hrs to 72 hrs Study Design: Randomized, Parallel Group, Placebo Controlled Trial Method of generating randomization sequence:Computer generated randomization Method of allocation concealment:Sequentially numbered, sealed, opaque envelopes Blinding and masking:Participant, Investigator and Outcome Assessor Blinded