Maternal Cardiac Output Response to Rescue Norepinephrine and Phenylephrine Boluses in Patients With Severe Preeclampsia

Maternal Cardiac Output Response to Rescue Norepinephrine and Phenylephrine Boluses During Spinal Anesthesia for Caesarean Section in Patients With Severe Preeclampsia: a Randomized, Controlled Trial

The purpose of this study is to investigate the maternal cardiac output response to rescue norepinephrine and phenylephrine boluses for postspinal anesthesia hypotension in parturients with preeclampsia undergoing cesarean section.

Study Overview

• Status: Completed
• Conditions: Hemodynamic Instability
• Intervention / Treatment: Drug: Phenylephrine; Drug: Norepinephrine

Detailed Description

Preeclampsia, which affects 5% to 7% of parturients, is a significant cause of maternal and neonatal morbidity and mortality. Because of constricted myometrial spiral arteries with exaggerated vasomotor responsiveness, though blood pressure in parturients with preeclampsia are apparently higher than healthy parturients, placental hypoperfusion is more common. Spinal anesthesia is still the preferred mode of anesthesia in parturients with preeclampsia for cesarean section. In preeclampsia parturients, spinal anesthesia improve intervillous blood flow (provided that hypotension is avoided) which contribute to increase placental perfusion. Even so, 17-26% parturients with preeclampsia experienced postspinal anesthesia hypotension due to the extensive sympathetic block that occurred with spinal anesthesia. As a potential substitute drug for phenylephrine and ephedrine, norepinephrine has gained traction for use in parturients undergoing cesarean section. However, hemodynamic effects of the rescue norepinephrine bolus is still unknown. The purpose of this study is to investigate the maternal cardiac output response to rescue norepinephrine and phenylephrine boluses for postspinal anesthesia hypotension in parturients with preeclampsia undergoing cesarean section.

• Study Type: Interventional
• Enrollment (Actual): 40
• Phase: Not Applicable

Contacts and Locations

Study Locations

• China
  • Ningxia
    • Yinchuan, Ningxia, China
      • General Hospital of Ningxia Medical University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 45 years (Adult)
• Accepts Healthy Volunteers: No

Description

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 ≥180 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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Phenylephrine group; Rescue phenylephrine (75μg) was given when postspinal anesthesia hypotension occurred	Drug: Phenylephrine; A rescue phenylephrine (75μg) was given when postspinal anesthesia hypotension occurred within 30 minutes after spinal anesthesia; Other Names: Vasopressors
Experimental: Norepinephrine group; Rescue norepinephrine (6μg) was given when postspinal anesthesia hypotension occurred	Drug: Norepinephrine; A rescue norepinephrine (6μg) was given when postspinal anesthesia hypotension occurred within 30 minutes after spinal anesthesia; Other Names: Vasopressors

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cardiac output (CO)	Evaluated by the VIGILCO monitoring system.	1-30 minutes after spinal anesthesia.
Stroke volume (SV)	Evaluated by the VIGILCO monitoring system.	1-30 minutes after spinal anesthesia
Systemic vascular resistance (SVR)	Evaluated by the VIGILCO monitoring system.	1-30 minutes after spinal anesthesia

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
pH	From umbilical arterial blood gases.	Immediately after delivery
APGAR score	A= Appearance P=Pulse G=Grimace A=Attitude R=Respiration	1 min after delivery
APGAR score	A= Appearance P=Pulse G=Grimace A=Attitude R=Respiration	5 min after delivery
Partial pressure of oxygen (PO2)	From umbilical arterial blood gases.	Immediately after delivery
Base excess (BE)	From umbilical arterial blood gases.	Immediately after delivery
Overall stability of systolic blood pressure control versus baseline	Evaluated by performance error (PE)	1-30 minutes after spinal anesthesia
Overall stability of heart rate control versus baseline	Evaluated by performance error (PE)	1-30 minutes after spinal anesthesia
The incidence of post-spinal anesthesia hypotension	Systolic blood pressure (SBP) < 80% of the baseline	1-30 minutes after spinal anesthesia.
The incidence of severe post-spinal anesthesia hypotension.	Systolic blood pressure (SBP) < 60% of the baseline	1-30 minutes after spinal anesthesia.
The incidence of nausea and vomiting.	Presence of nausea and vomiting in patients after spinal anesthesia	1-30 minutes after spinal anesthesia
The incidence of bradycardia.	Heart rate < 60 beats/min.	1-30 minutes after spinal anesthesia
The incidence of hypertension.	Systolic blood pressure (SBP) >120% of the baseline.	1-30 minutes after spinal anesthesia

Collaborators and Investigators

• Sponsor: General Hospital of Ningxia Medical University
• Investigators: Study Chair: Xiangzhao Xu, M.D.; Ph. D, The People's Hospital of Nanchuan; Study Chair: Yi Chen, M.D., General Hospital of Ningxia Medical University

Study record dates

Study Major Dates

• Study Start (Actual): September 13, 2022
• Primary Completion (Actual): January 21, 2024
• Study Completion (Actual): January 21, 2024

Study Registration Dates

• First Submitted: September 2, 2021
• First Submitted That Met QC Criteria: September 2, 2021
• First Posted (Actual): September 5, 2021

Study Record Updates

• Last Update Posted (Actual): February 2, 2024
• Last Update Submitted That Met QC Criteria: January 31, 2024
• Last Verified: January 1, 2024

More Information

Terms related to this study

• Keywords: Cesarean section; Norepinephrine; Preeclampsia; Phenylephrine; Cardiac output response
• Additional Relevant MeSH Terms: Pregnancy Complications; Hypertension, Pregnancy-Induced; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Pre-Eclampsia; Physiological Effects of Drugs; Adrenergic Agents; Neurotransmitter Agents; Molecular Mechanisms of Pharmacological Action; Autonomic Agents; Peripheral Nervous System Agents; Protective Agents; Adrenergic alpha-Agonists; Adrenergic Agonists; Cardiotonic Agents; Respiratory System Agents; Sympathomimetics; Mydriatics; Nasal Decongestants; Adrenergic alpha-1 Receptor Agonists; Norepinephrine; Phenylephrine; Oxymetazoline; Vasoconstrictor Agents
• Other Study ID Numbers: Yi Chen-2021-2

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No