Norepinephrine and Phenylephrine for Spinal Anesthesia-induced Hypotension.

General Hospital of Ningxia Medical University

Status

Not yet enrolling

Conditions

Outcome

Treatments

Drug: Norepinephrine

Drug: Phenylephrine

Study type

Interventional

Funder types

Other

Identifiers

NCT06508359

Yi Chen-2025-1

Details and patient eligibility

About

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.

Full 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.

Enrollment

2,000 estimated patients

Sex

Female

Ages

18 to 45 years old

Volunteers

No Healthy Volunteers

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

Trial design

Primary purpose

Treatment

Allocation

Randomized

Interventional model

Crossover Assignment

Masking

Double Blind

2,000 participants in 4 patient groups

Prophylactic norepinephrine group

Experimental group

Description:

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.

Treatment:

Drug: Norepinephrine

Prophylactic phenylephrine group

Experimental group

Description:

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.

Treatment:

Drug: Phenylephrine

Rescue norepinephrine group

Active Comparator group

Description:

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.

Treatment:

Drug: Norepinephrine

Rescue phenylephrine group

Active Comparator group

Description:

Treatment:

Drug: Phenylephrine