Effectiveness of Prophylactic Bolus Phenylephrine on the Prevention of Postspinal Hypotension During Elective Cesarean Section at Gandhi Memorial Hospital, Ethiopia 2024, Observational Prospective Cohort Study

Introduction: Spinal anesthesia owing to the perceived advantages is commonly used for caesarean section. However parturient under spinal anesthesia frequently experience hypotension and if it is severe it can result in morbidity for both the mother and the fetus. The incidence of hypotension during spinal anesthesia for caesarean section is reduced by administering intravenous fluids, drugs such as vasopressors, or by leg elevation. But in the practice of anesthesia preventing and treating hypotension associated with spinal anesthesia continue to be a challenging issue and there is controversy about the best way to handle it. Objective: The objective of this study is to determine the effectiveness of prophylactic bolus phenylephrine on the prevention of post-spinal hypotension during elective caesarean section under spinal anesthesia. Method: Observational cohort study design was conducted at Gandhi Memorial Hospital located in Addis Ababa, Ethiopia from February 01, 2024 to May 15, 2024. The sample size was determined by using the double population proportion method using manual calculator. Statistical package for social sciences (SPSS) software version 27.0 was used for data analyses. Comparison of numerical data between study groups was done by using independent sample t-test for symmetrical data and Mann whitney U test was used to compare non parametrical data. Chi square test was used to compare categorical data of the group. Values are presented as mean SD for symmetric data and median (IQR) for asymmetric data. For categorical data values are presented by number percent. Significance was determined at P value <0.05. Result: The incidence of hypotension in standard care group was 63.3% but in phenylephrine prophylactic group the incidence of hypotension was 28.6% [N: 105), P: 0.004]. Starting from the induction until 25 th minute, phenylephrine group had higher mean value of systolic and diastolic blood pressure than standard care group (P<0.05). Incidence of nausea, incidence of vomiting, numbers of mothers that require rescue vasopressor and total dose of rescue vasopressor were significantly different between the groups. Heart rate differences between phenylephrine and standard care group were not statistically significant Conclusion and recommendation: In conclusion, parturient undergoing elective caesarean section experienced less episode of hypotension after spinal anesthesia when a prophylactic bolus phenylephrine was used. Administering 100 microgram of bolus phenylephrine immediately after spinal anesthesia is recommended for better hemodynamic stability of the mothers