Comparative evaluation of intrathecal anaesthetic efficacy of combination of hyperbaric levobupivacaine with morphine versus hyperbaric bupivacaine with morphine in caesarean section- a double blinded randomized clinical trial

90parturients, belonging American Society of Anaesthesiologists Physical status(ASA-PS) class II planned for elective lower segment caesarean section (LSCS)under spinal anaesthesia (SA), will be thoroughly evaluated as a part ofpreanaesthetic evaluation, 24hours prior to the procedure. Fasting of 6 hoursfor solids and 2 hours for clear liquids will be ensured. Intravenous (IV)access will be secured in the ward as per our institutional policy. Allpatients will be randomised into two groups using shuffled sealed opaqueenvelop (SNOSE) technique.

GroupB- Will receive 10mg (2ml) of 0.5%hyperbaric bupivacaine-(H) and 100mcg morphine.

GroupL- Will receive 10mg(2ml) of 0.50 %hyperbaric levobupivacaine (H) and 100mcg morphine.

Toensure blinding, the anaesthesiologist who performs spinal anaesthesia will notbe further involved in the study. A different anaesthesiologist designated asthe observer will only enter the operation theatre after spinal anaesthesia hasbeen administered. Neither the observer nor the parturient will be disclosedany information regarding which drug to be administered. Hence the observer andthe parturient will be blinded for the study.

Inthe operation theatre standard monitoring devices will be attached, includingelectrocardiography (ECG), automated NIBP (non-invasive blood pressure), pulseoximetry (SpO2) and baseline values of SBP (systolic bloodpressure), DBP (diastolic blood pressure), MAP (mean arterial pressure) will berecorded. The hemodynamic multiparameter monitor will be placed in the directline of vision of the anaesthesiologist performing the Spinal Anaesthesia.Spinal anaesthesia will be administered using 25 G Quincke’s needle at theL2–L3 or L3–L4 interspace in sitting position. Immediately after administrationof spinal anaesthesia, the parturient will be made to lie down in supineposture with 10 cm wedge beneath the right buttock.

Intraoperativelysensory blockade will be checked using pin prick method and motor blockade willbe checked by modified Bromage score. The level of sensory and motor block willbe assessed every 1 minute for the 1st 10 minutes and every 5minutes till the completion of the surgery. Surgery will be allowed to startonce the sensory level reaches T6 level.

Anyhypotension, defined as a decrease in systolic blood pressure of < 20% belowbaseline, will be managed using 6 mg of intravenous ephedrine.

Heartrate will be monitored every minute for the first 10 mins and every 5 mins forthe next 30mins Any bradycardia with heart rate < 60bpm will be managed byusing 0.6mg of intravenous atropine.

Perioperativelysubjects will be followed up till they regain their motor power and sensation. Inthe immediate postoperative period, all patients will receive intravenous Inj.Paracetamol 1g 6th hourly. Postoperative analgesia will be assessed usingVAS score and a rescue analgesic of Inj. Diclofenac will be given if the VASscore is found to be greater than or equal to 3.