INTRODUCTION: Spinal anaesthesia is the gold standard for caesarean delivery despite associated side effects of hypotension, bradycardia & post dural puncture headache. Incidence of PDPH has decreased with the advent of newer needles. Variation in doses of spinal anaesthesia have been used for caesarean section. The purpose of our study is to compare the incidence of hypotension, & associated nausea & vomiting in parturients receiving height adjusted dose and fixed dose of 0.5% hyperbaric bupivacaine for caesarean delivery under spinal anaesthesia.
MATERIAL AND METHODS: This was a randomized double blind clinical trial. Ethics committee approval was taken. After randomization, 110 patients were assigned into two study groups. Group H:Height-adjusted dose of 0.5 percent bupivacaine heavy (0.06 mg/cm) with 10µg fentanyl was given to patientwhilein Group F fixed dose 2 ml of 0.5% bupivacaine heavy with 10µg fentanyl was used. The research was carried in a double-blind manner.The patient and the anaesthesiologist who were involved in patient monitoring and management after administration of the study drug were both blinded to the group assignment.
RESULTS: 110 full term parturient with singleton uncomplicated pregnancy of ASA physical status grade I or II, aged >18 years were considered. Although many factors affect volume of local anaesthetic like weight, height and dose,only height is taken into account in group H for calculating height adjusted dosages, whereas fixed doses are used in groups F. The mean total volume of drug administered to group H patients was 2.09 ml which is significantly lower than the mean total amount of drug given to group F patients which was 2.2 ml.P value was <0.001which is significant. There was no statistically significant difference between the mean heart rate, oxygen saturation, mean blood pressure, and diastolic blood pressure measurements. Only in reading of systolic blood pressure statistically significant difference was noted in initial minutes which was managed by small bolus dose of injection mephentermine.
CONCLUSION:The height adjusted dose of 0.5 percent hyperbaric bupivacaine when used for caesarean patient provides better haemodynamic stability with a decreased incidence of hypotension, less use of vasopressors although similar incidence of nausea and vomiting in comparison to those receiving a fixed dose of 0.5% hyperbaric bupivacainein patient of caesarean delivery under spinal anaesthesia.