The Potency of Prophylactic Norepinephrine and Phenylephrine Boluses for Postspinal Anesthesia Hypotension

Sponsor

General Hospital of Ningxia Medical University (Other)

Overall Status

Not yet recruiting

CT.gov ID

NCT05035472

Collaborator

(none)

Enrollment

Arms

Anticipated Duration (Months)

Study Details

Study Description

Brief Summary

The purpose of this study is to investigate the potency between prophylactic norepinephrine and phenylephrine boluses for postspinal anesthesia hypotension in patients with severe preeclampsia during caesarean section.

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

Detailed Description

Preeclampsia, which affects 5% to 7% of patients, 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 patients with preeclampsia are apparently higher than healthy patients, placental hypoperfusion is more common. Spinal anesthesia is still the preferred mode of anesthesia in patients with preeclampsia for cesarean section. In preeclampsia patients, spinal anesthesia improve intervillous blood flow (provided that hypotension is avoided) which contribute to increase placental perfusion. Even so, 17-26% patients 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 patients undergoing cesarean section. However, the ED50 (prevent postspinal hypotension in 50% of patients) and ED90 of prophylactic norepinephrine bolus is still unknown. The purpose of this study is to investigate the potency between prophylactic norepinephrine and phenylephrine boluses for postspinal anesthesia hypotension in patients with severe preeclampsia during caesarean section.

Study Design

Study Type:

Interventional

Anticipated Enrollment :

80 participants

Allocation:

Randomized

Intervention Model:

Parallel Assignment

Masking:

Double (Participant, Care Provider)

Primary Purpose:

Treatment

Official Title:

Comparison of the Potency of Prophylactic Norepinephrine and Phenylephrine Boluses for Postspinal Anesthesia Hypotension in Patients With Severe Preeclampsia During Caesarean Section

Anticipated Study Start Date :

Jan 1, 2023

Anticipated Primary Completion Date :

Dec 31, 2023

Anticipated Study Completion Date :

Dec 31, 2023

Arms and Interventions

Arm	Intervention/Treatment
Active Comparator: Phenylephrine group Prophylactic phenylephrine bolus simultaneous with spinal anesthesia	Drug: Phenylephrine An initial prophylactic bolus dose of phenylephrine (37.5μg) simultaneous with spinal anesthesia. If the patient did not respond adequately to the current dose (SBP decreased to < 80% of baseline), the dose was considered to have failed and the subsequent dose for the following patient was increased to the next higher dose level. The dose administered to subsequent patients varied by increments or decrements of 12.5 μg according to the responses of previous patients according to the up-down sequential allocation. Other Names: Vasopressors
Experimental: Norepinephrine group Prophylactic norepinephrine bolus simultaneous with spinal anesthesia	Drug: Norepinephrine An initial prophylactic bolus dose of norepinephrine (3μg) simultaneous with spinal anesthesia. The dose administered to subsequent patients varied by increments or decrements of 1 μg according to the responses of previous patients according to the up-down sequential allocation. Other Names: Vasopressors

Arm

Intervention/Treatment

Active Comparator: Phenylephrine group

Prophylactic phenylephrine bolus simultaneous with spinal anesthesia

Drug: Phenylephrine

An initial prophylactic bolus dose of phenylephrine (37.5μg) simultaneous with spinal anesthesia. If the patient did not respond adequately to the current dose (SBP decreased to < 80% of baseline), the dose was considered to have failed and the subsequent dose for the following patient was increased to the next higher dose level. The dose administered to subsequent patients varied by increments or decrements of 12.5 μg according to the responses of previous patients according to the up-down sequential allocation.

Other Names:

Vasopressors

Experimental: Norepinephrine group

Prophylactic norepinephrine bolus simultaneous with spinal anesthesia

Drug: Norepinephrine

An initial prophylactic bolus dose of norepinephrine (3μg) simultaneous with spinal anesthesia. The dose administered to subsequent patients varied by increments or decrements of 1 μg according to the responses of previous patients according to the up-down sequential allocation.

Other Names:

Vasopressors

Outcome Measures

Primary Outcome Measures

The dose that would be effective in preventing postspinal anesthesia hypotension in 50% (effective dose, ED 50) and 90% (ED90) of patients [1-15 minutes after spinal anesthesia]
Systolic blood pressure (SBP) < 80% of the baseline

Secondary Outcome Measures

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
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 (PO2) [Immediately after delivery]
From umbilical arterial blood gases.
Base excess (BE) [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