METHODOLOGY

 After approval from  local ethical committee of R.G.Kar Medical College and Hospital  with proper patient’s informed  consent, this prospective, randomized, double blinded clinical trial will planned to  be conducted in neurosurgical operation theater   from Octobor 2025 to September  2026.Total 60 patients aged  18 to 65 years , class I and II American Society of Anesthesiologists physical status, posted for lumber fixation surgery  will be included in this study.

.Patients with coagulation disorders, hepatic or renal impairment, previous heart surgery, uncooperative patients and patients with a history of allergy to any of the study drugs will be excluded from the study.

Total 96  patients will be randomly allocated using a computerized random number generator into two groups: Group P (48 patients) will receive 2 capsules of pregabalin 75 mg 2 hours before the operation,

Group D (30 patients) will receive intranasal dexmedetomedine at a dose of 2µg/kg(total 1ml ,0.5ml on each nostril) 45 minutes prior to the operation .

 To  make identical, group P will receive  1 ml NS 45min before operation and group D will receive 2 placebo capsules 2 hr before operation. In preoperative area, IV access will be secured and Ringer lactate infusion will be started.

All patients, nursing stuff and drug providers will be blinded to the nature of the injected drugs .Sealed envelopes containing group allocation will be obtained 2 hours before the operation

  In operation theatre (OT) all the standarized ASA monitors like electrocardiography( ECG),pulse oximeter,Non Invasive Blood Pressure(NIBP) will be attached and monitored through out the operation. Baseline values will be noted before anaesthesia and general anaesthesia (GA) will be administered to all as per standarized protocol.

Premedication to be given with Inj. Midazolam (0.05mg/kg) iv,

 Intravenous (IV) induction will be  done with injection( Inj). Fentanyl (2 mcg/kg) iv ,Inj. Loxicard (1 mg/kg )and  Inj. Propofol (2 mg/kg) . IV rocuronium will be administered for .Endotracheal intubation (ET ) .Patients will be maintained with N2O and O2 mixture in 1:1 ratio, inhalational isoflurane 0.5-1% to maintain bispectral index <50  and Inj. Atracurium (0.1 mg/kg) will be administered on  SOS if TOF count >. Intraoperative pulse, Blood pressure (BP), oxygen saturation (SPO2) will be monitored at 30 min interval till the end of operation.

Intra operatively whenever there will be increase in BP and Heart Rate by more than 20% from pre-operative baseline value, will  be  treated with intravenously IV  Fentanyl bolus 20 mcg . at the end of operation ,all the patients will be reversed with IV Myopyrrolate 5 ml (0.5 mg Glycopyrrolate plus 2.5 mg neostigmine). After extubation, pt will be shifted to recovery room and shifted to neurosurgical CCU for immediate 24 hrs after operation. Postoperatively analgesia will be assessed wit Visual analog scale at every 4 h intervals. Intravenous paracetamol 15mg/ kg administered as base line analgesic. IV tramadol 2mg/kg will be administered if VAS score >4.

Duration of analgesia will be considered as primary outcome and postoperative total IV  tramadol requirement, intra and postoperative haemodynamics and any postoperative adverse effect like nausea , vomiting will be considered as secondary outcome.