90% Effective Dose of Phenylephrine Infusions Under Intensive and Standard Treatment

NCT ID: NCT06151522

Last Updated: 2023-11-30

Basic Information

• Recruitment Status: NOT_YET_RECRUITING
• Clinical Phase: NA
• Total Enrollment: 80 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-04-01
• Study Completion Date: 2025-06-30

Brief Summary

The objective of this study is to investigate the 90% effective dose of phenylephrine infusions for preventing postspinal anesthesia hypotension under intensive and standard treatment 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 90% effective dose of phenylephrine infusions for preventing postspinal anesthesia hypotension under intensive and standard treatment during cesarean section.

Conditions

Adverse Effect

Study Design

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

Study Groups

Standard 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.

Group Type: OTHER

Alpha-Agonist

Intervention Type: DRUG

An initial infusion dose of prophylactic phenylephrine (0.625 ug/kg/min) simultaneous with spinal anesthesia. The dose administered to subsequent patients varied by increments or decrements of 0.125 ug/kg/min of prophylactic phenylephrine according to the responses of previous patients according to the up-down sequential allocation.

Intensive 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: OTHER

α-adrenergic receptor agonist

Intervention Type: DRUG

An initial infusion dose of prophylactic phenylephrine (0.625 ug/kg/min) simultaneous with spinal anesthesia. The dose administered to subsequent patients varied by increments or decrements of 0.125 ug/kg/min of prophylactic phenylephrine according to the responses of previous patients according to the up-down sequential allocation.

Interventions

Alpha-Agonist

An initial infusion dose of prophylactic phenylephrine (0.625 ug/kg/min) simultaneous with spinal anesthesia. The dose administered to subsequent patients varied by increments or decrements of 0.125 ug/kg/min of prophylactic phenylephrine according to the responses of previous patients according to the up-down sequential allocation.

Intervention Type: DRUG

α-adrenergic receptor agonist

An initial infusion dose of prophylactic phenylephrine (0.625 ug/kg/min) simultaneous with spinal anesthesia. The dose administered to subsequent patients varied by increments or decrements of 0.125 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

norepinephrine; norepinephrine

Eligibility Criteria

Inclusion Criteria

• 18-45 years
• Primipara or multipara
• Singleton pregnancy ≥37 weeks
• American Society of Anesthesiologists physical status classification I to 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 ≥180 mmHg
• Hemoglobin < 7g/dl

• 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

Central Contacts

Yi Chen, M.D.

Role: CONTACT

Phone: +86-951-674-3252

Email: czzyxgp@163.com

Other Identifiers

Yi Chen-2024-4

Identifier Type: -

Identifier Source: org_study_id