Reduction in spinal induced hypotension with ondansetron in parturients undergoing caesarean section

Abstract

Background: 5 HT-3 receptors are believed to be involved in the mechanism of post spinal hypotension. Prophylactic use of 5 HT-3 receptor blocking agents should attenuate hypotension associated with spinal anesthesia. Aims and Objectives: To study efficacy of ondansetron on hemodynamic parameters, nausea and vomiting and neonatal APGAR score in parturients undergoing caesarean section. Materials and Methods: Sixty parturients scheduled for elective caesarean section under spinal anesthesia were divided into two groups to receive ondanseton Group 1(n=30) or normal saline Group 2(n=30): prior to spinal anesthesia. Hemodynamic parameters (heart rate, systolic and diastolic blood pressure) and oxygen saturation were recorded at baseline, at 1,2 minutes after spinal anesthesia, and then after every 2 minutes interval up to 20 minutes followed by 5 minutes interval up to 40 minutes. Dose of intravenous phenylephrine and atropine used during the procedure, neonatal parameters (APGAR score) were recorded. Statistical analysis was done by students t-test for continuous variables and Fischers test and chi-square test for categorical variables. All p values were two-tailed. Results: Patients in Group 2 had lower heart rate as compared to patients in Group 1(p value<0.05). Systolic, diastolic and mean blood pressure were also lower in Group 2 as compared to group 1(p value<0.05). Vasopressor requirement was more in group 2 as compared to group 1.(pvalue<0.05) The incidence of nausea and vomiting was higher in group 2 as compared to group 1(p value<0.05). Neonatal APGAR scores were comparable between the two groups. Conclusion: Prophylactic ondansetron 4mg provided better hemodynamic stability and incidence of nausea and vomiting in patients undergoing caesarean section under spinal anesthesia without any effect on APGAR scores.