Management of Postspinal Anesthesia Hypotension During Elective Cesarean Section: Baby Norepinephrine Versus Ephedrine

Background : Spinal anesthesia emerges as the preferred anesthesia technique for elective cesarean section . It offers a preferable alternative to general anesthesia because it provides better maternal safety and neonatal outcomes. However, spinal anesthesia is not free of inherent risks. Hypotension remains the most common complication which threats both mother and child. The common method of treating hypotension includes fluid loading and the use of vasopressors such as ephedrine and phenylephrine. One promising approach is the administration of diluted norepinephrine. It presents a good alternative to preserve maternal blood pressure while minimizing adverse effects on the mother and fetus. Thus, our study proposes to evaluate the efficacy and safety of diluted norepinephrine boluses compared with ephedrine on the management of post- spinal anesthesia hypotension during scheduled cesarean sections. Patients and methods : After local Ethical Commitee approval, this prospective randomized double -blind study will be undertaken from August to October 2024 in the Department of Anesthesiology and Intensive care and Gynecology and Obstetric department of Charles Nicolle Hospital of Tunis. After obtaining informed written consent, singleton full-term pregnant females of ASA grade II, aged 18-38 years, scheduled for elective cesarean section under spinal anesthesia will be randomly divided into two groups. Group N : patients receive norepinephrine boluses (8 µg) ; prophylactic bolus immediately after spinal anesthesia induction and therapeutic boluses when systolic blood pressure falls to ≤ 20% of baseline. Group E : parturients receive ephedrine boluses (6 mg) ; systematic bolus after the induction of spinal anesthesia and therapeutic boluses if hypotension. Heart rate, systolic, diastolic and mean blood pressure are monitored. Number of episodes of hypotension and number of vasopressor boluses used in each group are recorded and considered as the primary outcomes of the study. Complication during the surgery as incidence of hypertension, tachycardia, bradycardia, nausea and vomiting are recorded. We also record neonatal APGAR score at 1 minute and five minutes. These parameters are considered as the secondary outcomes of the study. Statistical study: Data entry and analysis will be performed by SPSS software version 25.0. We will use Excel 2019 software to edit the charts. Continuous quantitative variables following a normal distribution will be expressed by their means and standard deviation. Categorical variables will be expressed as frequencies and percentages. Analytical study: We'll use the Pearson chi2 test or Fischer's exact test, whichever appropriate, for the comparison of categorical variables. T test of Student and Mann Whitney U-test will be employed for comparing Continuous variables. We 'll retain a significance threshold for p less than 5%.