Dose-Dependent Effects Of Bupivacaine On Maternal Hemodynamics In Combined Spinal-Epidural Anesthesia For Cesarean Delivery

ObjectiveTo study dose-dependent effects on maternal hemodynamics of bupivacaine in combined-spinal epidural anesthesia for cesarean section.MethodsNinety patients ready for caesarean section were recruited and randomly divided into three groups(groups A, B and C with 30 cases for each group)and received combined spinal--epidural anesthesia(CSEA).Patients were injected intratheca-lly with 0.5% bupivacaine (0.75%bupivacaine 2ml+NSlml) 1.3ml(group A),<160cm 1.2ml 160-165cml.3ml 165-1701.4 ml>170 1.5ml(group B) and 1.0ml+2% epidural lidocaine 3ml(group C) Additional 2% lidocaine were added if necessary. If the systolic pressure was less than 90mmHg or the diastolic pressure was 20% less than standard values,10mg ephedrine would be used to correct it. After these steps, all medical indexes were observed as follows:time from anesthesia to skin incision and operation time were recorded; meanwhile the blockade effective-ness, and the dosage of additional use of epidural 2% lidocaine as well as patients heart rate, blood pressure, and blood oxygen saturation at each post-anesthetic time interval were recorded. Apgar scores of the neonate, side effects such as nausea, vomiting hypotension and chest distress were also observed.ResultsStatistical analysis were performed by SPSS 16.0. ANOVA(analysis of variance) and Chi-square tests were used. The standard level of significance used to justify a claim of a statistically significant effect was 0.05.Major results were listed as follows. there were no difference in year, height, weight, time from anesthesia to skin incision and operation time among three groups. Dosage of additional use of epidural 2% lidocaine in group A and group B were less than group C (P<0.05).Dosage of ephedrine in group A and group B were more than group C. Systolic pressures at post-anesthetic 5 minute,10minute in group A correspondingly were lower than group respectively (P<0.05), and at delivery group A and group B were lower than group C (P<0.05).Diastolic pressure at post-anesthetic 10 minute group A was lower than group C (P<0.05).But there was no difference at other times among three groups(P >0.05). Also there were no differences in terms of heart rate, SPO2, Apgar scores of the neonate, nausea,vomit and chest distress among three groups (P>0.05). Hypotension in group A and group B were more often than group C(P<0.05).Conclusion0.5% bupivacaine 5 mg spinal anesthesia combined epidural 2% lidocaine 3 ml can provide reliable anesthesia and has the minimal effect on maternal hemodynamics.There was no difference between fixed dose group 1.3ml and height adjusted dose group.