Norepinephrine and Phenylephrine for Spinal Anesthesia-induced Hypotension.

Prophylactic vs Rescue Norepinephrine and Phenylephrine for Spinal Anesthesia-induced Hypotension on Neonatal Outcomes During Cesarean Section: A Multicenter, Single-blind, Crossover, Factorial Cluster Trial

This study aims to explore the effects of different application modes (prophylactic and rescue strategy) of norepinephrine and norepinephrine on neonate umbilical artery pH undergoing cesarean section.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Spinal anesthesia-induced hypotension is a frequent complication during spinal anesthesia for cesarean section. The incidence of spinal anesthesia-induced hypotension is as high as 62.1-89.7% if prophylactic measures are not taken. The 2016 ASA guidelines for obstetric anesthesia suggest avoiding hypotension following spinal anesthesia in women and emphasize the use of vasopressors, specifically alpha-receptor agonists, as the preferred strategy to prevent and manage spinal anesthesia-induced hypotension. The prophylactic vasopressor strategy is more effective in enhancing hemodynamic stability and reducing adverse events such as nausea and vomiting during cesarean section, compared to rescue strategy. However, it does not demonstrate significant advantages in neonatal outcomes such as umbilical artery pH and Apgar score. The impact of various vasopressor application patterns on neonatal outcomes after cesarean section lacks further supporting evidence. Therefore, this study aims to explore the effects of different application modes (prophylactic and rescue strategy) of norepinephrine and norepinephrine on neonate umbilical artery pH undergoing cesarean section through a multicenter, single-blind, 2*2 crossover and cluster randomized trial.

Study Type

Interventional

Enrollment (Actual)

700

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

    • Ningxia
      • Yinchuan, Ningxia, China, 750004
        • General Hospital of Ningxia Medical University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • 18-45 years
  • Primipara or multipara
  • Singleton pregnancy ≥37 weeks
  • American Society of Anesthesiologists physical status classification II
  • Scheduled for cesarean section under spinal anesthesia

Exclusion Criteria:

  • Body height < 150 cm
  • Body weight > 100 kg or body mass index (BMI) ≥ 40 kg/m2
  • Eclampsia or chronic hypertension or baseline blood pressure ≥140 mmHg
  • Hemoglobin < 7g/dl
  • Fetal distress, or known fetal developmental anomaly

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Prophylactic norepinephrine group
A maintenance dose of norepinephrine (0.05 ug/kg/min) infusion simultaneous with spinal anesthesia. The maternal systolic blood pressure was consistently maintained above 80% of the preoperative baseline value from the initiation of spinal anesthesia until fetal delivery.
Prophylactic or rescue norepinephrine for spinal anesthesia-induced hypotension
Other Names:
  • Vasopressor
Experimental: Prophylactic phenylephrine group
A maintenance dose of phenylephrine (0.625 ug/kg/min) infusion simultaneous with spinal anesthesia. The maternal systolic blood pressure was consistently maintained above 80% of the preoperative baseline value from the initiation of spinal anesthesia until fetal delivery.
Prophylactic or rescue phenylephrine for spinal anesthesia-induced hypotension
Other Names:
  • Vasopressor
Active Comparator: Rescue norepinephrine group
The maternal systolic blood pressure was consistently maintained above 80% of the preoperative baseline value from the initiation of spinal anesthesia until fetal delivery. Spinal anesthesia-induced hypotension is managed by administering a 6 μg intravenous bolus of norepinephrine.
Prophylactic or rescue norepinephrine for spinal anesthesia-induced hypotension
Other Names:
  • Vasopressor
Active Comparator: Rescue phenylephrine group
The maternal systolic blood pressure was consistently maintained above 80% of the preoperative baseline value from the initiation of spinal anesthesia until fetal delivery. Spinal anesthesia-induced hypotension is managed by administering a 75 μg intravenous bolus of phenylephrine.
Prophylactic or rescue phenylephrine for spinal anesthesia-induced hypotension
Other Names:
  • Vasopressor

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
pH
Time Frame: Immediately after delivery
From umbilical arterial blood gases.
Immediately after delivery
Base excess (BE)
Time Frame: Immediately after delivery
From umbilical arterial blood gases.
Immediately after delivery

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
The incidence of post-spinal anesthesia hypotension
Time Frame: 1-15 minutes after spinal anesthesia
Systolic blood pressure (SBP) < 80% of the baseline
1-15 minutes after spinal anesthesia
The incidence of severe post-spinal anesthesia hypotension
Time Frame: 1-15 minutes after spinal anesthesia
Systolic blood pressure (SBP) < 60% of the baseline
1-15 minutes after spinal anesthesia
The incidence of nausea and vomiting
Time Frame: 1-15 minutes after spinal anesthesia
Presence of nausea and vomiting in patients after spinal anesthesia
1-15 minutes after spinal anesthesia
The incidence of bradycardia
Time Frame: 1-15 minutes after spinal anesthesia
Heart rate < 60 beats/min
1-15 minutes after spinal anesthesia
APGAR score
Time Frame: 1 min after delivery
A= Appearance P=Pulse G=Grimace A=Attitude R=Respiration
1 min after delivery
APGAR score
Time Frame: 5 min after delivery
A= Appearance P=Pulse G=Grimace A=Attitude R=Respiration
5 min after delivery
Partial pressure of oxygen (PO2)
Time Frame: Immediately after delivery
From umbilical arterial blood gases.
Immediately after delivery
The incidence of hypertension
Time Frame: 1-15 minutes after spinal anesthesia
Systolic blood pressure (SBP) >120% of the baseline.
1-15 minutes after spinal anesthesia

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Investigators

  • Study Chair: Yi Chen, M.D., General Hospital of Ningxia Medical University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

August 1, 2025

Primary Completion (Actual)

April 21, 2026

Study Completion (Actual)

April 21, 2026

Study Registration Dates

First Submitted

July 14, 2024

First Submitted That Met QC Criteria

July 14, 2024

First Posted (Actual)

July 18, 2024

Study Record Updates

Last Update Posted (Actual)

April 28, 2026

Last Update Submitted That Met QC Criteria

April 27, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

  • Yi Chen-2025-1

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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