Phenylephrine Prophylaxis for Postspinal Anesthesia Hypotension in Parturients With Preeclampsia

Not Applicable

Not yet recruiting

• Conditions: Adverse Effect
• Interventions: Drug: Normal saline; Drug: Phenylephrine

• Registration Number: NCT04576663
• Lead Sponsor: General Hospital of Ningxia Medical University

Brief Summary

The purpose of this study is to investigate the suitable infusion dose of phenylephrine for prophylaxis against postspinal anesthesia hypotension in parturients with preeclampsia undergoing cesarean section.

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. Practical guidelines for obstetric anesthesia from the American Society of Anesthesiologists and an international consensus statement on the management of hypotension with vasopressors indicate either IV ephedrine or phenylephrine may be used to correct hypotension. But the suitable infusion dose of phenylephrine in parturients with preeclampsia is still unknown. The purpose of this study is to investigate the suitable infusion dose of phenylephrine for prophylaxis against post-spinal anesthesia hypotension in parturients with preeclampsia undergoing cesarean section.

Study Timeline

• Study First Submitted: 2020-09-30
• Study First Submitted QC: 2020-09-30
• Study First Posted: 2020-10-06
• Status Verified: 2021-09
• Last Update Submitted: 2021-11-25
• Last Update Posted: 2021-11-29
• Study Start: 2023-10-01
• Primary Completion: 2025-09-21
• Study Completion: 2025-09-21

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: Female
• Target Recruitment: 95

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 & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Control group	Normal saline	Normal saline infusion simultaneous with subarachnoid block
0.3125 μg/kg/min group	Phenylephrine	A maintenance dose of phenylephrine (0.3125 μg/kg/ min) infusion simultaneous with subarachnoid block
0.9375 μg/kg/min group	Phenylephrine	A maintenance dose of phenylephrine (0.9375 μg/kg/ min) infusion simultaneous with subarachnoid block
0.625 μg/kg/min group	Phenylephrine	A maintenance dose of phenylephrine (0.625 μg/kg/ min) infusion simultaneous with subarachnoid block

Primary Outcome Measures

Name	Time	Method
The incidence of post-spinal anesthesia hypotension	1-15 minutes after spinal anesthesia	Systolic blood pressure (SBP) \< 80% of the baseline

Secondary Outcome Measures

Name	Time	Method
Overall stability of heart rate control versus baseline	1-15 minutes after spinal anesthesia	Evaluated by performance error (PE)
APGAR score	5 min after delivery	A= Appearance P=Pulse G=Grimace A=Attitude R=Respiration
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.
Partial pressure of oxygen	Immediately after delivery	From umbilical arterial blood gases.
Base excess	Immediately after delivery	From umbilical arterial blood gases.
Overall stability of systolic blood pressure control versus baseline	1-15 minutes after spinal anesthesia	Evaluated by performance error (PE)
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 nausea and vomiting	1-15 minutes after spinal anesthesia	Presence of nausea and vomiting in patients after spinal anesthesia
The incidence of bradycardia	1-15 minutes after spinal anesthesia	Heart rate \< 60 beats/min