A comparative study of intrathecal hyperbaric bupivacaine Vs hyperbaric levobupivacaine with morphine as an additive for lower segment caesarean section: A prospective randomised double blind clinical trail

Methodology

Institutional ethics committee approval obtained. Following written informed consent, study will start recruiting the parturient. Parturient with singleton pregnancy, ASA 2, aged 18-45years, scheduled for caesarean section will be considered for this prospective, randomised, double blind study. Parturients who are ASA III, IV, patients in active labour, patient with coagulopathies, allergic to drugs used in the study, patients withmultiple gestation, abnormal placentation and those with severe preeclampsia will be excluded from the study. Patients will be randomly divided in to two groups: Group B and group L using computer generated random number table. To ensure blinding, the spinal anaesthesia drugs will be prepared by another anaesthesiologist, who is not directly involved in the subsequent anaesthetic management. Patients will not know their group allocation and hence ensuring the double-blind study.

Pre anaesthetic evaluation will be done 24hours before the scheduled surgery time for all parturient. Parturient will be given pantoprazole 40 mg orally at bedtime. Parturient will fasted a minimum of 6 hour preoperatively. Large bore IV access will be secured and intravenous co-loading with 1liter of crystalloid will started along with spinal anaesthesia. A pulse oximeter, non-invasive blood pressure, electrocardiogram will be connected. Heart rate, ECG will be monitored continuously and NIBP will be recorded every minute till baby delivery and then once every 5 minutes till end of surgery. With patient in sitting position, under aseptic precautions intrathecal injection will be given at L2-L3 or L3-L4 space using 26g Quincke spinal needle. Parturient in Group B will receive 10mg of hyperbaric bupivacaine 0.5% (2ml) plus morphine 100mcg (diluted in 0.1ml), and those in group L will receive 10mg of hyperbaric levobupivacaine 0.5(2ml)plus morphine 100mcg (diluted in 0.1ml) in spinal anaesthesia.

The patient will receive spinal drug as per the group allocation. Immediately after block the patient will be positioned in supine position with a 150leftward tilt on the operating table. If maternal hypotension, defined as a fall in blood pressure [BP] >20% from the baseline or systolic BP <100 mmHg occurred,it will be promptly treated with 50mcg bolus of phenylephrine. Total amount of vasopressors used will be noted. Bradycardia defined as heart rate < 50bpm will be treated with 0.5mg iv atropine. Sensory block will be assessed bilaterally by pin prick method, and the degree of motor block will be determined according to the Bromage scale (0: free movements of legs and feet; 1: just able to flex knees, free movements of feet; 2: unable to flex knees, free movement of feet; 3: unable to move legs or feet). After intrathecal injection, sensory and motor block assessments will be performed everyminute until for first 10 minutes, and subsequently at 5-min intervals until the maximum block height is reached, as indicated by same value for consecutive three readings. Time of baby delivery, APGAR score will be noted, patient will be shifted to PACU and thereafter, spinal block characteristics will be assessed at 15minutes intervals until complete recovery of motor function will be determined. Time needed for 2 segment regression of spinal anaesthesia and time for block regression to T10 will be noted. Patients will be assessed for postoperative pain using Visual Analogue Scale of 0-10 and will be given Intravenous Diclofenac 75mg infusion for VAS>3, up to two doses. If the pain persists, then Tramadol 50mg infusion will be given. Postoperative pain scores and analgesic requirement will be noted every 6th hourly up to 48 hours postoperatively. The presence of adverse effects, including nausea, vomiting, pruritus, shivering, backache or post-dural puncture headache during the first 48 hour after spinal anaesthesia, as well as any treatment requirements, will be noted.