COMPARISON OF DEXMEDETOMIDINE AND FENTANYL AS AN ADJUVANT TO ROPIVACAINE FOR EPIDURAL ANALGESIA IN ABDOMINAL HYSTERECTOMY REGARDING QUALITY OF POSTOPERATIVE ANALGESIA.

This prospective, randomised controlled, double blind study will be conducted on 60 patients belonging to the ASA physical status 1 or 2, aged 30 - 60 years posted for elective abdominal hysterectomy.

Pre-anaesthetic check up will be done a day before surgery including a detailed history,a thorough physical and systemic examination. Routine investigations will include CBC, routine urine test, ECG, serum urea, serum creatinine, blood sugar and chest radiograph. In the operating room standard monitoring will be established (ECG, Non-invasive Blood pressure, pulse oximetry) and baseline measurements will be recorded. Under aseptic precautions, epidural catheter will be placed using 18 G Touhy needle with patients in the sitting position in L3-L4 interspace and location of epidural space will be confirmed using loss of resistance technique. A test dose of 3 ml of 2% Lignocaine with adrenaline will be administered into epidural space and thereafter epidural catheter will be secured 3 to 5 cm into epidural space and patient will be placed in the supine position. Heart rate, mean arterial pressure, SPO2 will be recorded using standard monitors before and after epidural test dose. General anaesthesia will be induced with Propofol (1.5-2mg/kg) + Succinyl choline(1.5mg/kg) + Fentanyl (2 µg/kg) and maintained with O₂, N₂O and Isoflurane. Muscle relaxation will be done with vecuronium 4mg and then 1mg intermittently. The respective drugs depending on the group allocated will be given by epidural infusion at the rate of 7ml/hr (Ropivacaine (0.125 %) +1µg/ml Dexmedetomidine or Ropivacaine (0.125%) +2µg /ml Fentanyl) into the epidural space 1hr after the skin incision using syringe pump. After extubation, the patient will be put on PCEA pump with study drug with background infusion

of 5ml/hr(Ropivacaine (0.125 %) +1µg/ml Dexmedetomidine or Ropivacaine (0.125%) +2µg /ml Fentanyl), demand bolus dose of 2ml, lock-out interval of 10 min (Maximum dose=10ml/hr). The degree of motor block will be assessed by the Modified Bromage scale:

Bromage 0 – able to perform a full straight leg raise over the bed for 5 sec

Bromage 1 – unable to perform the leg raise but can flex the leg on the knee articulation.

Bromage 2 – unable to flex the knee but can flex the ankle.

Bromage 3 – unable to flex ankle but can move the toes.

Bromage 4 – unable to move toes (total paralysis).

Post-operative pain scores will be recorded using visual analogue scale (VAS) ranging from 0 to 10 (0 – no pain ,10- worst pain ever) at 0,1,2,4,8,12,16,20,24 hours.

Patients with breakthrough pain will be given 25µg Fentanyl IV bolus. Rescue analgesia requirement will be noted and side effects if any will be addressed accordingly.