Effectiveness and Safety of Prophylactic Intravenous Bolus Phenylephrine in Prevention of Spinal Anesthesia Induced Hypotension during Cesarean Section: A Prospective Observational Study in University of Gondar Hospital, Northwest Ethiopia, 2017

Abstract

Abstract Introduction: Hypotension is one of the frequent complications of spinal anaesthesia with an incidence of greater than 80%.It is due to sympathetic blockade during spinal anesthesia and it will be more aggravated due to aortocaval compression, high spinal block and physiological changes of pregnancy to subarachnoid space. It has many detrimental effects to the mother and fetus if left untreated. As it has been managed by pharmacologic and non-pharmacologic methods, phenylephrine was found to be important to prevent and treat post-spinal hypotension. Objective: This study was designed to determine the effectiveness of intravenous phenylephrine bolus in the prevention of hypotension after spinal anaesthesia for parturients underwent caesarean section. Method: A Prospective Observational Study was conducted after obtaining ethical approval from institutional review board. Statistical analysis was performed using SPSS statistical package version 20. The incidence of hypotension was analyzed by using chi-square test. In addition to incidence of hypotension, the hemodynamic changes over time between the groups were analyzed by repeated measures of ANOVA for separate line plots and compared by using independent student t-test. All numeric variables were checked by Shapiro wilk test for their normality and those normal and non-normal parameters were analyzed by using independent ttest and mann whitney test respectively. P value < 0.05 was considered statistically significant. Numerical data were presented as a mean ± Standard deviation and median (interquartile range) and categorical data as proportions (%). Results: The incidence of hypotension was significantly lower for those participants with prophylactic phenylephrine (26% Vs 81.6%, p<0.001). The intraoperative vital signs were compared between groups. Systolic and diastolic blood pressure immediately after SA till delivery and after delivery of the baby were significantly lower for those without prophylactic drug for hypotension with p<0.05 all the time. The number of rescue treatment and total amount of fluid given in intraoperative period for treatment of hypotension were more for participants not given phenylephrine prophylactically(p=0.001). The APGAR score at 1st and 5th minute and postoperative vital signs were not different significantly between groups. Conclusion: This study demonstrates that, prophylactic dose of phenylephrine was effective to prevent spinal induced hypotension. Recommendation: It is good to use prophylactic phenylephrine for prevention of spinal induced hypotension. Key words: Apgar score, cesarean section, hypotension, phenylephrine, prophylaxis, spinal anesthesia