Phenylephrine Prophylaxis for Postspinal Anesthesia Hypotension in Parturients With Preeclampsia

Sponsor

General Hospital of Ningxia Medical University (Other)

Overall Status

Not yet recruiting

CT.gov ID

NCT04576663

Collaborator

(none)

Enrollment

Arms

23.7

Anticipated Duration (Months)

Study Details

Study Description

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.

Condition or Disease	Intervention/Treatment	Phase
Adverse Effect	Drug: Normal saline Drug: Phenylephrine	N/A

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 Design

Study Type:

Interventional

Anticipated Enrollment :

95 participants

Allocation:

Randomized

Intervention Model:

Parallel Assignment

Masking:

Triple (Participant, Care Provider, Outcomes Assessor)

Primary Purpose:

Treatment

Official Title:

Phenylephrine Prophylaxis for Postspinal Anesthesia Hypotension in Parturients With Preeclampsia Undergoing Cesarean Section: a Randomized, Placebo-controlled Dose-finding Trial

Anticipated Study Start Date :

Oct 1, 2023

Anticipated Primary Completion Date :

Sep 21, 2025

Anticipated Study Completion Date :

Sep 21, 2025

Arms and Interventions

Arm	Intervention/Treatment
Placebo Comparator: Control group Normal saline infusion simultaneous with subarachnoid block	Drug: Normal saline Normal saline infusion simultaneous with subarachnoid block Other Names: NS
Experimental: 0.3125 μg/kg/min group A maintenance dose of phenylephrine (0.3125 μg/kg/ min) infusion simultaneous with subarachnoid block	Drug: Phenylephrine Different infusion dose of phenylephrine simultaneous with subarachnoid block Other Names: Vasopressors
Experimental: 0.625 μg/kg/min group A maintenance dose of phenylephrine (0.625 μg/kg/ min) infusion simultaneous with subarachnoid block	Drug: Phenylephrine Different infusion dose of phenylephrine simultaneous with subarachnoid block Other Names: Vasopressors
Experimental: 0.9375 μg/kg/min group A maintenance dose of phenylephrine (0.9375 μg/kg/ min) infusion simultaneous with subarachnoid block	Drug: Phenylephrine Different infusion dose of phenylephrine simultaneous with subarachnoid block Other Names: Vasopressors

Outcome Measures

Primary Outcome Measures

The incidence of post-spinal anesthesia hypotension [1-15 minutes after spinal anesthesia]
Systolic blood pressure (SBP) < 80% of the baseline

Secondary Outcome Measures

Overall stability of systolic blood pressure control versus baseline [1-15 minutes after spinal anesthesia]
Evaluated by performance error (PE)
Overall stability of heart rate 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
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.
APGAR score [1 min after delivery]
A= Appearance P=Pulse G=Grimace A=Attitude R=Respiration
APGAR score [5 min after delivery]
A= Appearance P=Pulse G=Grimace A=Attitude R=Respiration