Haemodynamic Changes and Onset of Sensory Block during Caesarean Section using Isobaric 0.5% and Hyperbaric 0.75% Bupivacaine Intrathecally

Abstract

Objective: To compare the results of isobaric 0.5% and hyperbaric 0.75% bupivacaine intrathecally in same dose (12mg) in the cases of caesarean section, in respect to mean time of onset of sensory block and mean haemodynamic changes (mean systolic blood pressure and mean heart rate). Study Design: Randomized controlled trial. Place & Duration: Department of Anaesthesiology, Surgical Intensive Care Unit & Pain Management and Department of Obstetrics and Gynaecology, Peoples Medical University Hospital Nawabshah from March 2015 to September 2015. Material & Methods: Sample size was 140 pregnant women, who were divided into two groups (IB &. HB) each group contained 70 patients and randomly allocated by envelope method. 1B received 12mg (2.4 ml) of isobaric 0.5% bupivacaine hydrochloride intrathecally and HB received 12mg (1.6m1) of hyperbaric 0.75% bupivacaine hydrochloride intrathecally. Prior to spinal anaesthesia 15mlikg lactated Ringer's solution in sitting position was given for preloading. Patients were positioned supine with 15 degree left lateral tilt after injection of bupivacaine. Onset of block was assessed. Heart rate and blood pressure were monitored throughout surgery. The final outcome was measured as mean systolic blood pressure & mean heart rate at the end of the procedure. SPSS version 10.0 was utilized for data analysis. Results: In group IB 4.60 ± 0.86 minutes was the time of onset of sensory block as compared to 4.407 ± 0.85 minutes in group HB. Significant difference was not observed between groups (p=0.183). The mean systolic blood pressure recorded in group IB was 117.07±16.97 mmHg and 116.19±4.89 mmHg in group HB. Significant difference was not observed between groups in mean systolic blood pressure 0.87±0.211 (95%CI of difference: -3.29 to 5.05). Similarly difference in mean heart rate was also not significant between groups 0.316±1.45 (95% CI of difference: -2.55 to 3.18). Conclusion: The differences observed in time of onset of sensory block, mean systolic blood pressure and in mean heart rate were not significant.