ED90 of Norepinephrine and Phenylephrine Infusions Under Intensive Treatment in Preeclamptic Patients

Not Applicable

Recruiting

• Conditions: Adverse Effect
• Interventions: Drug: Phenylephrine; Drug: Norepinephrine

• Registration Number: NCT06158022
• Lead Sponsor: General Hospital of Ningxia Medical University

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

Study Timeline

• Study First Submitted: 2023-11-25
• Study First Submitted QC: 2023-11-28
• Study First Posted: 2023-12-06
• Status Verified: 2024-10
• Study Start: 2024-10-03
• Last Update Submitted: 2024-12-02
• Last Update Posted: 2024-12-04
• Primary Completion: 2025-07-30
• Study Completion: 2025-07-30

Recruitment & Eligibility

• Status: RECRUITING
• Sex: Female
• Target Recruitment: 80

Inclusion Criteria

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

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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

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

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

Primary Outcome Measures

Name	Time	Method
ED50 and ED90	1-15 minutes after spinal anesthesia	The doses of prophylactic norepinephrine and phenylephrine that would be effective in preventing postspinal anesthesia hypotension in 50% (effective dose, ED 50) and 90% (ED90) of patients

Secondary Outcome Measures

Name	Time	Method
The incidence of hypertension.	1-15 minutes after spinal anesthesia.	Systolic blood pressure (SBP) \>120% of the baseline.
pH	Immediately after delivery	From umbilical arterial blood gases.
Base excess (BE)	Immediately after delivery	From umbilical arterial blood gases.
Partial pressure of oxygen (PO2)	Immediately after delivery	From umbilical arterial blood gases.
APGAR score	5 min after fetal delivery	A= Appearance P=Pulse G=Grimace A=Attitude R=Respiration; 0(Worst)-10(Best)
The incidence of post-spinal anesthesia hypotension	1-15 minutes after spinal anesthesia.	Systolic blood pressure (SBP) \< 80% of the baseline
The incidence of severe post-spinal anesthesia hypotension.	1-15 minutes after spinal anesthesia.	Systolic blood pressure (SBP) \< 60% of the baseline.
The incidence of bradycardia.	1-15 minutes after spinal anesthesia.	Heart rate \< 60 beats/min.
The incidence of nausea and vomiting.	1-15 minutes after spinal anesthesia.	Presence of nausea and vomiting in patients after spinal anesthesia

Trial Locations

Locations (1)

General hospital of Ningxia University; 🇨🇳 Yinchuan, Ningxia, China