Effect of pregabalin on Total knee replacement post operative pain

INTERVENTION: 120 patients fulfilling the inclusion criteria will be included in this study. The patients will be randomly assigned into two equal groups; Group P: Pregablain group and Group C: control group. Group P will receive oral capsule pregabalin 75mg one hour preoperatively and Group C will not receive any premedication preoperatively. To ensure adherence to the intervention, empty drug blister will be returned to pharmacy. Intraoperatively both groups will receive Inj. midazolam 2mg before subarachnoid block with hyperbaric Bupivacaine 0.5% 2.5‐3ml and fentanyl 15mcg in the operation theatre (OT). Both groups will also receive parecoxib 40mg IV and paracetamol 1G Intravenous (IV) as part of multimodal analgesia. Both groups will receive dexamethasone 8mg IV prophylactically. Postoperatively both group will receive Ultrasound guided Adductor canal Femoral Nerve block in the PACU with 0.2% Bupivacaine & dexmeditomidine1.0mcg/kg. Group P will receive oral capsule pregabalin 75 mg Q12hrly from the 1st dose for next 60 hrs. Group C will not receive any medication. Both groups will receive paracetamol 1G IV Q6Hrly for 24 hrs. Rescue Analgesia will be provided with oral oxycodone 5mg TDS and Morphine S/C 4‐5mg, in escalating manner as per patient requirement. CONDITION: Anaesthesiology ‐ Pain management postoperative Pain;Total knee replacement; ; postoperative Pain ; Total knee replacement PRIMARY OUTCOME: To measure Total Knee replacement Postoperative Pain by Visual Analogue Score 0‐10[ Postoperative at 4hrs, 8hrs, 12hrs, 24hrs, 36 hrs, 48hrs, 60hrs, and 72hrs.] SECONDARY OUTCOME: Patient satisfaction at 72 hrs : rated as numeric 1‐5 (1=not satisfied, 5=fully satisfied) ; [ Postoperative 72 Hrs] Sedation score[ Sedation score: RASS score postoperative at 4hrs, 8hrs, 12hrs, 24hrs, 36 hrs, 48hrs, 60hrs, 72hrs. ; ] Total Opioids consumption at 72 hrs ; assessed from medical records of OPIODS Consumption, kept by nursing staff. [ post operative 72 hrs] INCLUSION CRITERIA: 1. Age between 21 to 85 year 2. Elective Regional anesthesia. 3. Able to follow study protocol