Norepinephrine vs. Phenylephrine for Spinal Hypotension in Cesarean Section

Universitas Sumatera Utara

Status: Completed

Conditions: Pregnancy Complications; Anesthesia Spinal; Cesarean Resection; Hypotenstion; Cardiovascular

Treatments: Drug: Norepinephrine 4mcg; Drug: Phenylephrine 50 mcg

Study type: Interventional

Funder types: Other

Identifiers

NCT07153601

103/KEPK/USU/2025

Details and patient eligibility

About

This clinical trial was conducted to compare the effectiveness and safety of two medications-norepinephrine and phenylephrine-in treating low blood pressure (hypotension) that often occurs during spinal anesthesia for cesarean section (C-section) deliveries. Spinal anesthesia is commonly used during C-sections but can cause a drop in the mother's blood pressure, which may affect both the mother and the baby.

In this study, 46 pregnant women undergoing elective C-sections were randomly given either norepinephrine (4 mcg) or phenylephrine (50 mcg) when their blood pressure dropped. Researchers monitored their heart rate, blood pressure, and any side effects for 30 minutes after anesthesia.

The results showed that both drugs were effective in raising blood pressure. However, norepinephrine kept the heart rate more stable, while phenylephrine caused a noticeable slowing of the heart rate (bradycardia). Both drugs were safe and well tolerated.

This study suggests that norepinephrine may be a better option for managing low blood pressure during spinal anesthesia in C-sections, especially when maintaining heart rate and cardiac output is important.

Enrollment: 46 patients

Sex: All

Ages: 18+ years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Female patients aged 18-40 years
• Undergoing elective cesarean section
• Receiving spinal anesthesia
• Classified as ASA Physical Status II
• Stable baseline hemodynamics prior to anesthesia
• Not using inotropic, chronotropic, or vasoactive drugs before surgery

Exclusion criteria

• Emergency cesarean section
• Fetal distress
• Preeclampsia or eclampsia
• Contraindications to spinal anesthesia (e.g., coagulopathy, infection at injection site)
• Known allergy to norepinephrine or phenylephrine
• Hemodynamic instability prior to vasopressor administration
• Withdrawal from study or refusal to participate
• Failure to develop post-spinal hypotension

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Quadruple Blind

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46 participants in 2 patient groups

Norepinephrine Group

Experimental group

Description:

Participants in this group received intravenous bolus doses of norepinephrine 4 mcg (2 mL) diluted in normal saline to treat spinal anesthesia-induced hypotension during cesarean section.

Treatment:

Drug: Norepinephrine 4mcg

Phenylephrine Group

Experimental group

Description:

Participants in this group received intravenous bolus doses of phenylephrine 50 mcg (2 mL) diluted in normal saline to treat spinal anesthesia-induced hypotension during cesarean section

Treatment:

Drug: Phenylephrine 50 mcg