The effect of baricity and density of intrathecal administered bupivacaine on maternal hemodynamics and motor block in patients undregoing caesarean section

The aim of this study was to compare maternal hemodynamics and motor block recovery of intrathecally administered three different baricity of bupivacaine 0.5 % for caesarean section.Ninety parturients scheduled for caesarean section were randomly allocated into 3 groups: ( n=30). In Group H, 12.5 mg of hyperbaric bupivacaine 0.5 %; in Group I, 12.5 mg of isobaric bupivacaine 0.5 % and in Group M, 12.5 mg of bupivacaine from the mixture of 9.4 cc of isobaric bupivacaine 0.5 % and 0.6 cc of hyperbaric bupivacaine 0.5 % was administered by spinal route. After intrathecal injection of study drug via combined spinal epidural technique, the catheter inserted to epidural space and parturient turned to supine position. Sensorial and motor block level, blood pressure and heart rate variables were recorded every 2 minutes for the first 10 minutes time and every 5 minutes thereafter until the 60th minute. When sensorial block didn?t reach to T4 level before surgical incision, an additional dose of 5 mL isobaric bupivacaine 0.5 % was administered through the epidural catheter.. If the patients experienced intraoperative pain, either the additional dose of the local anaesthetic via epidural catheter or an IV bolus dose of 25 ?g of fentanyl was administered.T4 sensorial blockage was supplied in all groups. Time to reach the sensorial block to T4 level in Group H, Group I and Group M were 7.06 ? 2.73 minutes, 5.06 ? 2.33 minutes and 5.76 ? 2.73 minutes, respectively. When compared with the other groups, time to reach the sensorial block to T4 level was significantly shorter in the Group I, in which 12.5 mg of isobaric bupivacaine 0.5 % was administered (p< 0.05).No significant difference was found in hemodynamic parameters, motor and sensorial block characteristics when compared within and among the groups (p> 0.05).In conclusion, intrathecal administration of hyperbaric, isobaric or mixture of hyperbaric and isobaric forms of 12.5 mg of bupivacaine % 0.5 by combined spinal epidural anaesthesia in patients undergoing Caeserean section provided sufficient anaesthesia. Nevertheless, the baricity and density of intrathecal solution had no effect on hemodynamic parameters, motor and sensorial block characteristics. Time to reach the sensorial block to T4 level was significantly shorter in the Group I.Keywords: Baricity, density, bupivacaine, Caesarean section, combined spinal epidural anaesthesia