Abstract
Background: Hypotension due to spinal anesthesia is a common complication among obstetric patients and may be worse when there is high-risk pregnancy. Several factors ensure the sufficient provision of fetal health including effective vasopressor therapy to restore maternal blood pressure and sufficient uteroplacental perfusion.
Objective: To determine the difference between the efficacy of phenylephrine, norepinephrine, and ephedrine in managing spinal induced hypotension in high risk obstetric patients undergoing cesarean delivery.
Methods: This was an observational study that involved 43 high-risk obstetric patients who acquired hypotension after administering spinal anesthesia. Regular monitoring of hemodynamic parameters was done. The hypotensive episodes and the duration of the hypotensive episode, maternal symptoms, and Apgar scores at birth of each patient were recorded. It assessed the clinical response of the selected vasopressor administered by the attending anesthetist (phenylephrine, norepinephrine or ephedrine).
Results: Phenylephrine showed the most positive results, and it was able to stabilize the blood pressure quickly and with only one short-lived hypotension incident in all the patients, and no complications in the mother. Norepinephrine was found to be moderately effective and a number of patients were found to have a number of, but non-prolonged hypotensive episodes. The poorest control was observed with ephedrine, recurrent episodes were frequent, the length of hypotension was greater, and the frequency of some maternal side effects like vomiting and shivering increased. The most successful results were also in the phenylephrine group, as all the neonates had normal Apgar scores, and lower scores prevailed in the norepinephrine and ephedrine groups.
Conclusion: Phenylephrine is the most effective and safest vasopressor to use in treatment of the spinal-induced hypotension in high-risk obstetric patients, as it provides better maternal hemodynamic stability and the best neonatal outcomes. Norepinephrine is also a sensible option in the absence of phenylephrine although ephedrine is not as effective and needs to be administered carefully.