A clinical trial to study the effects of two drugs clonidine and butorphanol as an adjuvant to hyperbaric levobupivacaine in spinal anaesthesia in lower limb surgeries

INTERVENTION: Intervention1: RANDOMIZED CONTROLLED TRIAL: After getting Institutional Ethics Committee approval, patients will be randomly allocated into two groups via computer generated randomization method to receive a total volume of 3.3ml of drug solution intrathecally. Group A: 3ml(15mg) of 0.5% hyperbaric levobupivacaine + 45mcg clonidine intrathecally. Group B: 3ml(15mg) of 0.5% hyperbaric levobupivacaine + 0.3mg butorphanol intrathecally. The masking of group allocation will be maintained using sealed opaque envelopes. The study drug will be prepared by an anaesthesiologist who will have no subsequent involvement in the study. After shifting the patient to the operating room, all standard anaesthesia monitors like Pulse Oximeter, Electrocardiogram and Non Invasive Blood Pressure (NIBP) will be connected and baseline vital parameters [blood pressure, heart rate and peripheral oxygen saturation (SpO2) will be recorded. Intravenous line with an 18G cannula be placed on non‐dominant hand and Ringer lactate solution will be started as preloading solution. Under proper aseptic conditions, lumbar puncture will be done with a 25G Quincke spinal needle at L3‐L4 intervertebral level in sitting position. After confirming the free flow of cerebrospinal fluid, 3.3ml of the study drug solution will be administered by an anaesthesiologist not aware of the drug solution. The sensory level will be assessed by the pinprick method using blunt 23 Gauge needle, while the motor block will be assessed by Modified Bromage Scale. The onset of sensory block will be defined as the time interval from the end of injection of intrathecal drug and the loss of pinprick sensation at T10 dermatome. The onset of motor block will be defined as the time taken from intrathecal injection to achieve a modified Bromage scale score of 3. Duration of sensory block will be defined as the time interval from the onset of sensory block to regression of block to S1 level. The duration of motor block will be defined as the time from intrathecal injection to regression to modified Bromage scale score of 0. Surgery will be allowed to start after achieving a sensory block level of T10, and a modified Bromage score of 3. DOSE:3.3ML FREQUENCY:ONCE ROUTE:INTRATHECALLY DURATION:2 HOURS Control Intervention1: Clonidine versus Butorphanol: Group A: 3ml that is 15mg of 0.5 percent hyperbaric levobupivacaine plus 45mcg clonidine intrathecally. Group B: 3ml that is 15mg of 0.5 percent hyperbaric levobupivacaine plus 0.3mg butorphanol intrathecally. CONDITION: Health Condition 1: M849‐ Disorder of continuity of bone, unspecified Health Condition 2: M80‐M85‐ Disorders of bone density and structure PRIMARY OUTCOME: Time of requirement of first dose of rescue analgesia in minutesTimepoint: 0,5,10,15,20,25,30,40,60,75,90,120 minutes SECONDARY OUTCOME: Time of onset of sensory block in minutes ; Time of onset of motor block in minutes ; Duration of sensory block in minutes ; Duration of motor block in minutes ; Hemodynamic changes ; Post operative VAS score ; Incidence of side effectsTimepoint: 1hr,2hr,4hr,6hr,12hr INCLUSION CRITERIA: Patient posted for lower limb surgery under spinal anaesthesia Age greater than 18 yrs ASA PS I & II