Ephedrine Versus Phenylephrine for Spinal Block - Related Hypotension in Cesarean Delivery

Active, not recruiting

• Conditions: Spinal Anesthesia; Cesarean Delivery; Neonatal Acidosis
• Interventions: Drug: Ephedrine; Drug: Phenylephrine

• Registration Number: NCT06741410
• Lead Sponsor: Centre of Postgraduate Medical Education

Brief Summary

The study is designed to compare two strategies used in the management of hypotension caused by spinal anesthesia for cesarean section: intravenous phenylephrine given as prophylactic infusion and interventional boluses of intravenous ephedrine. Phenylephrine is currently recommended for battling spinal anesthesia - related sympathectomy, due to some scientific data on possible negative effects of ephedrine on fetal wellbeing. Therefore this study will retrospectively compare both clinical and laboratory data of the newborns delivered by cesarean section where either large dose of ephedrine or continuous infusion of phenylephrine was used for management of hypotension

Detailed Description

Single - shot spinal block is a gold standard of anesthesia for cesarean delivery. It has been proven to decrease maternal morbidity and improve neonatal outcomes. Despite being most frequently used type of anesthesia in obstetrics, spinal block - related complications remain frequent in term parturients, of which hypotension is of utmost importance. Two widely accepted medications used in its prevention and treatment are phenylephrine and ephedrine, of which continuous, preventive phenylephrine infusion is considered superior in terms of neonatal safety.

Although there is some scientific evidence towards ephedrine having negative effect on neonatal acid - base status, it is still the most popular vasoconstrictor used for management of perioperative hypotension in Poland. It is an indirect adrenergic agonist, acting through release of noradrenaline from peripheral nerve endings. Beta - receptors mediated adrenergic stimulation of neonatal tissues is thought to be responsible for endocrine abnormalities, acid - base disturbances and possibly worse Apgar scores. Phenylephrine on the other hand is a direct and selective alpha-1 agonist and is regarded to exert very little or even no neonatal effects. Maternal complications related to phenylephrine infusion is hypertension and reflex bradycardia.

As convincing evidence is still lacking, this study is designed to retrospectively compare neonatal outcomes and perioperative hemodynamic data of mothers where either infusion of phenylephrine or boluses of ephedrine were used to control spinal -related hypotension during cesarean section.

Study Timeline

• Study First Submitted: 2024-12-11
• Study First Submitted QC: 2024-12-14
• Study Start: 2024-12-16
• Study First Posted: 2024-12-19
• Status Verified: 2025-05
• Last Update Submitted: 2025-05-05
• Last Update Posted: 2025-05-06
• Primary Completion: 2025-07
• Study Completion: 2025-08

Recruitment & Eligibility

• Status: ACTIVE_NOT_RECRUITING
• Sex: Female
• Target Recruitment: 80

Inclusion Criteria

• Cesarean delivery at term under spinal anesthesia
• American Society of Anesthesiologists (ASA) physical status <3
• BMI <40
• Preemptive phenylephrine infusion or ephedrine boluses used during surgical procedure

Exclusion Criteria

• No vasoconstrictor (phenylephrine nor ephedrine) used throughout the procedure
• Total dose of ephedrine less than 15mg
• poor quality of anesthetic record - data required for analysis not available

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
Ephedrine	Ephedrine	Cesarean delivery cases where spinal block was administered and hypotension was managed with intravenous ephedrine. Hospital electronic database will be searched to identify cases of cesarean delivery in years 2020 - 2022. After that, manual review of the medical notes will follow in order to extract cases where spinal block was administered and ephedrine was used to treat spinal - related hypotension. Further chart analysis will yield demographic and hemodynamic data of the parturient, as well as clinical data of the neonate (weight, gender, Apgar score). Further laboratory data on neonatal acid - base status will be acquired from hospital's laboratory electronic database. Attention will be paid to assure that identification of the patients would not be possible using data acquired for the study. All data will be anonymized and accessible only for investigators.
Phenylephrine	Phenylephrine	Cesarean delivery cases where spinal block was administered and hypotension was managed with intravenous phenylephrine infusion Hospital electronic database will be searched to identify cases of cesarean delivery in years 2020 - 2022. After that, manual review of the medical notes will follow in order to extract cases where spinal block was administered and infusion of phenylephrine was used to treat spinal - related hypotension. Further chart analysis will yield demographic and hemodynamic data of the parturient, as well as clinical data of the neonate (weight, gender, Apgar score). Further laboratory data on neonatal acid - base status will be acquired from hospital's laboratory electronic database. Attention will be paid to assure that identification of the patients would not be possible using data acquired for the study. All data will be anonymized and accessible only for investigators.

Primary Outcome Measures

Name	Time	Method
Umbilical blood pH	During delivery (from spinal injection to umbilical clamping and cutting)	Sets of data will be tested for normality and standard statistical tests (Student's t - test or Mann - Whitney U - test) will be used to detect the differences in umbilical blood pH between the groups.
Umbilical blood Base Excess (BE)	During delivery (from spinal injection to umbilical clamping and cutting)	Sets of data will be tested for normality and standard statistical tests (Student's t - test or Mann - Whitney U - test) will be used to detect the differences in umbilical blood Base Excess (BE) between the groups.

Secondary Outcome Measures

Name	Time	Method
Hemodynamic stability	During delivery (from spinal injection to umbilical clamping and cutting)	Number of episodes of hypotension recorded in anesthetic sheet after spinal injection will be compared using chi-square or Fisher's exact test.

Trial Locations

Locations (1)

Centre of Postgraduate Medical Education,Department of Anesthesia and Intensive Care; 🇵🇱 Warsaw, Poland