Enhancing spinal anesthesia with intrathecal injection of Fentanyl as adjuvant to hyperbaric Bupivacaine. Pharmacological or physical effect? A randomized controlled clinical study

After getting clearance from Institute Ethics Committee and written informed consent of eligible patients, 90 patients aged 18-60 years, American Society of Anesthesiology grade I and II scheduled for elective lower abdominal surgeries will be enrolled in this study. On arrival patients will be connected to monitor and thereafter will be randomly allocated to three groups of 30 patients each. the investigator will remain blinded to the group allocation and the drug used. Patients in group A will receive 0.5% hyperbaric Bupivacaine 3.0 ml (12.5mg) in 5.0 ml syringe. Group B will receive 0.5% hyperbaric Bupivacaine 3.0 ml in a 5.0 ml syringe followed by 0.5 ml of normal saline in 1.0 ml syringe. Group C will receive 0.5% of hyperbaric Bupivacaine 3.0 ml in 5.0 ml syringe followed by 0.5 ml (25 microgram) of Fentanyl in 1.0 ml syringe.

Subarachnoid block will be administered at L 3-4 intervertebral space in lateral decubitus position.

onset of sensory block will be assessed by sterile pin prick every 2min till 20 mins and then after every 10 mins till highest level will be achieved. Sensory onset will be defined as the loss of sensation at T10 level and motor onset when modified Bromage score turns 3. Time of regression of moto blockade will be assessed by modified Bromage score becomes 0.

Vital parameters of the patients will be assessed periodically till completion of procedure. Time till the requirement of first rescue analgesia will be recorded. Entire data would be entered into Microsoft office software, appropriate statistical test will be applied and results will be calculated.