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

Adverse Effect Clinical Trial

Official title:

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

Clinical Trial Details — Status: Not yet recruiting

Administrative data

• NCT number: NCT05035472
• Other study ID #: Yi Chen-2021-3
• Status: Not yet recruiting
• Phase: N/A
• Start date: January 1, 2023
• Est. completion date: December 31, 2023

Study information

• Verified date: September 2021
• Source: General Hospital of Ningxia Medical University
• Contact: Xinli Ni, Dr.
• Phone: 86-951-674-3252
• Email: xinlini6[@]nyfy.com.cn
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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.

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.

Recruitment information / eligibility

• Status: Not yet recruiting
• Enrollment: 80
• Est. completion date: December 31, 2023
• Est. primary completion date: December 31, 2023
• Accepts healthy volunteers: No
• Gender: Female
• Age group: 18 Years to 45 Years

Eligibility

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

Related Conditions & MeSH terms

• Adverse Effect
• Hypotension

Intervention

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.
• 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.

Locations

Country	Name	City	State
n/a

Sponsors (1)

Lead Sponsor	Collaborator
General Hospital of Ningxia Medical University

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	The dose that would be effective in preventing postspinal anesthesia hypotension in 50% (effective dose, ED 50) and 90% (ED90) of patients	Systolic blood pressure (SBP) < 80% of the baseline	1-15 minutes after spinal anesthesia
Secondary	The incidence of post-spinal anesthesia hypotension	Systolic blood pressure (SBP) < 80% of the baseline	1-15 minutes after spinal anesthesia
Secondary	The incidence of severe post-spinal anesthesia hypotension.	Systolic blood pressure (SBP) < 60% of the baseline	1-15 minutes after spinal anesthesia
Secondary	The incidence of bradycardia.	Heart rate < 60 beats/min.	1-15 minutes after spinal anesthesia
Secondary	The incidence of nausea and vomiting.	Presence of nausea and vomiting in patients after spinal anesthesia	1-15 minutes after spinal anesthesia
Secondary	The incidence of hypertension.	Systolic blood pressure (SBP) >120% of the baseline.	1-15 minutes after spinal anesthesia
Secondary	pH	From umbilical arterial blood gases.	Immediately after delivery
Secondary	Partial pressure of oxygen (PO2)	From umbilical arterial blood gases.	Immediately after delivery
Secondary	Base excess (BE)	From umbilical arterial blood gases.	Immediately after delivery
Secondary	APGAR score	A= Appearance P=Pulse G=Grimace A=Attitude R=Respiration	1 min after delivery
Secondary	APGAR score	A= Appearance P=Pulse G=Grimace A=Attitude R=Respiration	5 min after delivery