Effect of Ephedrine vs. Norepinephrine on Prevention of Fetal Acidosis During Cesarean Section Under Spinal Anesthesia

Phase 4

Not yet recruiting

• Conditions: Acidosis, Lactic; Hypotension After Spinal Anesthesia; Cesarean Delivery Affecting Newborn
• Interventions: Drug: Ephedrine; Drug: Norepinephrine

• Registration Number: NCT06921473
• Lead Sponsor: mehmet özkılıç

Brief Summary

This study compares the effects of two medications, ephedrine and norepinephrine, on the baby (fetus) when used to treat low blood pressure (hypotension) during cesarean section under spinal anesthesia. Hypotension is a common side effect during spinal anesthesia, and it can affect the blood flow to the baby. Both medications are commonly used to manage this condition. The goal of the study is to determine which medication is more effective and safer for the baby, by measuring the pH level in the umbilical artery after birth. The study will also examine maternal blood pressure, heart rate, and the baby's Apgar scores.

Detailed Description

This is a prospective, randomized, double-blind, controlled clinical trial designed to compare the effects of ephedrine and norepinephrine on fetal acidosis during cesarean section performed under spinal anesthesia. Maternal hypotension is a frequent complication associated with spinal anesthesia, and the management of this condition is critical for maintaining adequate uteroplacental perfusion. While both ephedrine and norepinephrine are commonly used vasopressors, there is ongoing debate regarding their relative safety and efficacy, particularly in terms of fetal outcomes.

The primary aim of this study is to evaluate the incidence of fetal acidosis, defined as an umbilical artery pH \< 7.20, in patients receiving either ephedrine or norepinephrine. Secondary outcomes include maternal blood pressure control, heart rate, incidence of maternal and fetal tachycardia, Apgar scores at 1 and 5 minutes, and the need for additional vasopressor support. A total of 100 pregnant women undergoing elective cesarean section will be enrolled, with 50 participants in each treatment group. All participants will receive standardized spinal anesthesia, and vasopressors will be titrated according to protocol.

The study is designed to inform clinical decision-making regarding optimal vasopressor selection in obstetric anesthesia, with a focus on balancing maternal hemodynamic stability and fetal well-being.

Study Timeline

• Study First Submitted: 2025-04-01
• Study First Submitted QC: 2025-04-08
• Study First Posted: 2025-04-10
• Status Verified: 2025-05
• Last Update Submitted: 2025-05-13
• Last Update Posted: 2025-05-16
• Study Start: 2025-06-01
• Primary Completion: 2026-01-12
• Study Completion: 2026-03-01

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: Female
• Target Recruitment: 100

Inclusion Criteria

• Pregnant women aged between 18 and 45 years
• Singleton pregnancy at ≥ 37 weeks of gestation
• Scheduled for elective cesarean section under spinal anesthesia
• ASA (American Society of Anesthesiologists) physical status classification I or II
• Ability to understand and sign the informed consent form

Exclusion Criteria

• History of allergy or hypersensitivity to ephedrine or norepinephrine
• Multiple gestation pregnancies
• Diagnosis of pre-eclampsia, eclampsia, or other hypertensive disorders of pregnancy
• Known cardiovascular disease or arrhythmia
• Placental abnormalities (e.g., placenta previa, placental abruption)
• Fetal structural or chromosomal anomalies
• Morbid obesity (BMI > 40 kg/m²)
• Refusal to participate or inability to provide informed consent

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Ephedrine Group	Ephedrine	Participants in this group will receive intravenous bolus doses of ephedrine (5-10 mg) to manage spinal anesthesia-induced hypotension during cesarean section.
Norepinephrine Group	Norepinephrine	Participants in this group will receive intravenous bolus doses of norepinephrine (5-10 µg) to manage spinal anesthesia-induced hypotension during cesarean section.

Primary Outcome Measures

Name	Time	Method
Incidence of fetal acidosis (umbilical artery pH < 7.20)	At delivery (within 5 minutes of birth)	Fetal acidosis is defined as an umbilical artery pH value below 7.20. The umbilical artery blood sample will be collected immediately after delivery from the clamped segment of the umbilical cord. The pH will be measured using a standard blood gas analyzer.

Secondary Outcome Measures

Name	Time	Method
Incidence of maternal tachycardia	During surgery	Maternal tachycardia is defined as a heart rate greater than 100 bpm recorded after vasopressor administration. Heart rate is continuously monitored using ECG. The outcome is the proportion of participants with tachycardia.
Incidence of maternal hypotension	During surgery (within 30 minutes after spinal anesthesia)	Maternal hypotension is defined as a systolic blood pressure decrease of more than 20% from baseline or below 90 mmHg. Blood pressure will be monitored noninvasively at regular intervals.