ED90 of Norepinephrine and Phenylephrine Infusions in Preeclamptic Patients

NCT ID: NCT06158022

Last Updated: 2025-10-06

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 60 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2024-10-03
• Study Completion Date: 2025-05-20

Brief Summary

The objective of this study is to investigate the ED90 of norepinephrine and phenylephrine infusions for preventing postspinal anesthesia hypotension under intensive treatment in preeclamptic patients during cesarean section

Detailed Description

Post-spinal anesthesia hypotension is a frequent complication during spinal anesthesia for cesarean section. The incidence of post-spinal anesthesia 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 post-spinal anesthesia hypotension. The 2018 International Consensus in the United Kingdom and Northern Ireland recommends maintaining maternal systolic blood pressure above 90% of the baseline value following lumbar anesthesia, while avoiding dropping below 80% of the baseline value. Currently, the threshold for maintaining blood pressure above 80% of the baseline value is widely adopted as a standard; however, limited evidence supports the advantage of sustaining maternal blood pressure above 90% of the baseline value. The objective of this study is to investigate the ED90 of norepinephrine and phenylephrine infusions for preventing postspinal anesthesia hypotension under intensive treatment in preeclamptic patients during cesarean section

Conditions

Adverse Effect

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: DOUBLE

Study Groups

Norepinephrine group

The maternal systolic blood pressure was consistently maintained above 90% of the preoperative baseline value from the initiation of spinal anesthesia until fetal delivery.

Group Type: EXPERIMENTAL

Norepinephrine

Intervention Type: DRUG

An initial infusion dose of prophylactic norepinephrine (0.05 ug/kg/min) simultaneous with spinal anesthesia. The dose administered to subsequent patients varied by increments or decrements of 0.01 ug/kg/min of prophylactic norepinephrine according to the responses of previous patients according to the up-down sequential allocation.

Phenylephrine group

The maternal systolic blood pressure was consistently maintained above 90% of the preoperative baseline value from the initiation of spinal anesthesia until fetal delivery.

Group Type: EXPERIMENTAL

Phenylephrine

Intervention Type: DRUG

An initial infusion dose of prophylactic phenylephrine (0.5 ug/kg/min) simultaneous with spinal anesthesia. The dose administered to subsequent patients varied by increments or decrements of 0.1 ug/kg/min of prophylactic phenylephrine according to the responses of previous patients according to the up-down sequential allocation.

Interventions

Norepinephrine

An initial infusion dose of prophylactic norepinephrine (0.05 ug/kg/min) simultaneous with spinal anesthesia. The dose administered to subsequent patients varied by increments or decrements of 0.01 ug/kg/min of prophylactic norepinephrine according to the responses of previous patients according to the up-down sequential allocation.

Intervention Type: DRUG

Phenylephrine

An initial infusion dose of prophylactic phenylephrine (0.5 ug/kg/min) simultaneous with spinal anesthesia. The dose administered to subsequent patients varied by increments or decrements of 0.1 ug/kg/min of prophylactic phenylephrine according to the responses of previous patients according to the up-down sequential allocation.

Intervention Type: DRUG

Other Intervention Names

Vasopressor; Vasopressor

Eligibility Criteria

Inclusion Criteria

• 18-45 years
• Primipara or multipara
• Singleton pregnancy ≥32 weeks
• American Society of Anesthesiologists physical status classification II to III
• Scheduled for cesarean section under spinal anesthesia

Exclusion Criteria

• Baseline blood pressure ≥160 mmHg
• Body height < 150 cm
• Body weight > 100 kg or body mass index (BMI) ≥ 40 kg/m2
• Eclampsia or chronic hypertension
• Hemoglobin < 7g/dl
• Fetal distress, or known fetal developmental anomaly

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 45 Years
• Eligible Sex: FEMALE
• Accepts Healthy Volunteers: No

Sponsors

General Hospital of Ningxia Medical University

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Yi Chen, M.D.

Role: STUDY_CHAIR

General Hospital of Ningxia Medical University

Locations

General hospital of Ningxia University

Yinchuan, Ningxia, China

Countries

China

Other Identifiers

Yi Chen-2024-11

Identifier Type: -

Identifier Source: org_study_id