Use of intravenous phenylephrine in continuous infusion in pregnant women undergoing elective cesarean section under spinal anesthesia

Abstract

Introduction: Arterial hypotension frequently occurs after spinal anesthesia for cesarean sections. Phenylephrine is a drug with selective alpha 1 action that is indicated as a bolus or continuous infusion for the treatment of arterial hypotension and has been considered for use in pregnant women. Objective: To evaluate the usefulness of intravenous infusion of phenylephrine to prevent arterial hypotension and its related adverse effects after spinal anesthesia in cesarean sections. Methodology: Pilot intragroup time series study in a population of 23 pregnant women undergoing cesarean section under spinal anesthesia. After spinal anesthesia and the infusion of phenylephrine at an initial dose of 0.5 micrograms/Kg/min, the values ​​of systolic blood pressure and heart rate were monitored in sequential measurements at minutes 3, 9 and 15 during the cesarean section procedure. Results: In most patients (95.6%), systolic blood pressure remained within the acceptable range of variation (decrease < 20%). When considering the mean arterial pressure, in 91% the values ​​were maintained within adequate limits at 3 minutes, 9 minutes and 15 minutes. The frequency of bradycardia was 21.7%. No nausea or vomiting was observed during the surgical procedure in pregnant women. Conclusion: The use of the initial dose of 0.5 mcg/Kg/min proved to be useful in many patients to prevent the side effects of spinal anesthesia in cesarean sections.