To compare the effect of Ketamine spray versus Dexmedetomidine spray at surgical site during closure in lumbar spine fixation surgery for postoperative pain relief - Prospective, Randomized, double blinded, placebo controlled study

The patients will be divided randomly using computer generated number and concealed using sequentially numbered, sealed opaque envelope technique into three equal groups:

Group D: Will receive Dexmedetomidine 1 microgram/kg diluted in normal saline to make 20ml solution and is sprayed over the surgical site towards the end of the surgery.

Group K: Will receive Ketamine 1 mg/kg diluted in normal saline to make 20 ml solution and is sprayed over the surgical site towards the end of the surgery.

Group C: Will receive 20 ml of normal saline and is sprayed over the surgical site towards the end of the surgery.

 Under standard General anaesthesia, Lumbar spine surgery will be done,

towards the end of surgery once the fixation will be done, Dexmedetomidine 1mcg/kg or Ketamine 1 mg/kg or normal salinewill be diluted in 0.9% Normal Saline to make 20 ml solution. This solution will be sprayed over the surgical site, thoracolumbar fascia, subcutaneous tissue using drug atomizer device which will atomize the drug and skin closure will be done. Patient will be turned supine and extubation will be done. VAS will be monitored at 30 mins after extubation, 1hr, 2h, 4h, 6h and 24h post extubation.  Patients will be given rescue analgesia if VAS (≥4/10), with inj tramadol 2mg/kg asslow intravenous with prior medication with 0.1mg/kg Ondansetron. If pain still persist then Inj paracetamol 1 gm iv [max 4 gm in 24 h]will be given over 20min. Such demand in first 24 h will be monitored for the study.