Abstract

The most frequent side effect of spinal anesthesia is hypotension, occurring in 60-89% of patients. The use of phenylephrine is associated with reflex bradycardia and greater fluctuations in heart rate and cardiac output when compared to norepinephrine. Continuous norepinephrine infusions have been shown to maintain maternal heart rate and cardiac output more effectively.

A 41-year-old female underwent a cesarean section under epidural anesthesia. Intraoperatively, the patient had multiple hypotensive episodes, which were managed by 5 bolus doses of phenylephrine and 4 doses of ephedrine. This case highlights the hemodynamic instability associated with intermittent phenylephrine boluses and raises the question of whether prophylactic norepinephrine infusions could provide a more stable maternal heart rate during cesarean deliveries.

Clinical Question: In parturients undergoing cesarean sections, does a prophylactic norepinephrine infusion compared to intermittent phenylephrine boluses lead to fewer fluctuations in the parturient’s heart rate in the perioperative period?

Evidence Based Discussion: The effects of maternal hypotension can lead to heart rate fluctuations, decreased cardiac output and uteroplacental blood flow, as well as nausea and vomiting. Standard hypotension management includes phenylephrine boluses to maintain normotension; however, due to its alpha-1 agonist properties and the baroreceptor reflex, bradycardia often follows its administration. Recent literature highlights norepinephrine as an alternative vasopressor due to its combined alpha and beta agonist effects, which support stable hemodynamic profiles. Both bolus and infusion administrations have been shown to minimize such fluctuations as seen with phenylephrine. Prophylactic administration of norepinephrine, defined as before or immediately after initiation of subarachnoid blockade (SAB), provides hemodynamic stability and requires fewer interventions throughout the intraoperative time.

Translation to Practice: Implementing a protocol for prophylactic norepinephrine infusion in parturients undergoing scheduled cesarean section under SAB would allow for the application of new evidence-based practices.

Author Details

Amanda Sullivan, DNP(c), BSN, RN - Critical Care Nurse, Student Registered Nurse Anesthetist | Lisa Herbinger DNP, CRNA, FAANA - Certified Registered Nurse Anesthetist

Sigma Membership

Non-member

Type

DNP Capstone Project

Format Type

Text-based Document

Study Design/Type

Case Study/Series

Research Approach

Translational Research/Evidence-based Practice

Keywords:

Cesarean Section, Norepinephrine, Phenylephrine, Spinal Anesthesia, Maternal Hypotension, Hypotension

Advisor

Terri M. Cahoon

Degree

DNP

Degree Grantor

Samford University

Degree Year

2026

Rights Holder

All rights reserved by the author(s) and/or publisher(s) listed in this item record unless relinquished in whole or part by a rights notation or a Creative Commons License present in this item record. All permission requests should be directed accordingly and not to the Sigma Repository. All submitting authors or publishers have affirmed that when using material in their work where they do not own copyright, they have obtained permission of the copyright holder prior to submission and the rights holder has been acknowledged as necessary.

Review Type

None: Degree-based Submission

Acquisition

Proxy-submission

Date of Issue

2026-02-02

Full Text of Presentation

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Abstract.pdf (187 kB)

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