Intensive Versus Standard Treatment for Spinal Anesthesia-induced Hypotension on Maternal Hemodynamics

Study Overview
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Brief Summary
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The objective of this study is to investigate the impact of varying maternal blood pressure maintenance targets on maternal hemodynamics following cesarean section.

Detailed Description
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Post-spinal anesthesia hypotension is a frequent complication during spinal anesthesia for cesarean section. The incidence of post-spinal anesthesia hypotension is as high as 62.1-89.7% if prophylactic measures are not taken. The 2016 ASA guidelines for obstetric anesthesia suggest avoiding hypotension following spinal anesthesia in women and emphasize the use of vasopressors, specifically alpha-receptor agonists, as the preferred strategy to prevent and manage post-spinal anesthesia hypotension. The 2018 International Consensus in the United Kingdom and Northern Ireland recommends maintaining maternal systolic blood pressure above 90% of the baseline value following lumbar anesthesia, while avoiding dropping below 80% of the baseline value. Currently, the threshold for maintaining blood pressure above 80% of the baseline value is widely adopted as a standard; however, limited evidence supports the advantage of sustaining maternal blood pressure above 90% of the baseline value. The objective of this study is to investigate the impact of varying maternal blood pressure maintenance targets on maternal hemodynamics following cesarean section.

Official Title
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Intensive Versus Standard Treatment for Spinal Anesthesia-induced Hypotension on Maternal Hemodynamics During Cesarean Section: A Multicenter, Prospective, Single-blind, Randomized, Controlled Trial

Conditions
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Outcome

Intervention / Treatment
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* Drug: Alpha-Agonist
* Drug: α-adrenergic receptor agonist


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 18-45 years Primipara or multipara Singleton pregnancy ≥37 weeks American Society of Anesthesiologists physical status classification I to II Scheduled for cesarean section under spinal anesthesia Exclusion Criteria: Body height < 150 cm Body weight > 100 kg or body mass index (BMI) ≥ 40 kg/m2 Eclampsia or chronic hypertension or baseline blood pressure ≥180 mmHg Hemoglobin < 7g/dl Fetal distress, or known fetal developmental anomaly

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Standard group<br>The maternal systolic blood pressure was consistently maintained above 80% of the preoperative baseline value from the initiation of spinal anesthesia until fetal delivery. | Drug: Alpha-Agonist<br>* The maternal systolic blood pressure was consistently maintained above 80% of the preoperative baseline value from the initiation of spinal anesthesia until fetal delivery.<br>* Other names: Vasopressors;|
| Experimental: Intensive group<br>The maternal systolic blood pressure was consistently maintained above 90% of the preoperative baseline value from the initiation of spinal anesthesia until fetal delivery. | Drug: α-adrenergic receptor agonist<br>* The maternal systolic blood pressure was consistently maintained above 90% of the preoperative baseline value from the initiation of spinal anesthesia until fetal delivery.<br>* Other names: Vasopressors;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cardiac output | Monitoring data | 1-15 minutes after spinal anesthesia. | 
| Cardiac index | Monitoring data | 1-15 minutes after spinal anesthesia. | 
| Stroke volume variation | Monitoring data | 1-15 minutes after spinal anesthesia. | 
| Peripheral vascular resistance | Monitoring data | 1-15 minutes after spinal anesthesia. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The incidence of post-spinal anesthesia hypotension | Systolic blood pressure (SBP) < 80% of the baseline | 1-15 minutes after spinal anesthesia. | 
| The incidence of severe post-spinal anesthesia hypotension. | Systolic blood pressure (SBP) < 60% of the baseline. | 1-15 minutes after spinal anesthesia. | 
| The incidence of bradycardia. | Heart rate < 60 beats/min. | 1-15 minutes after spinal anesthesia. | 
| The incidence of nausea and vomiting. | Presence of nausea and vomiting in patients after spinal anesthesia | 1-15 minutes after spinal anesthesia. | 
| The incidence of hypertension. | Systolic blood pressure (SBP) >120% of the baseline. | 1-15 minutes after spinal anesthesia. | 
| pH | From umbilical arterial blood gases. | Immediately after delivery | 
| Base excess | From umbilical arterial blood gases. | Immediately after delivery | 
| Partial pressure of oxygen (PO2) | From umbilical arterial blood gases. | Immediately after delivery | 
| APGAR score | A= Appearance P=Pulse G=Grimace A=Attitude R=Respiration; 0(Worst)-10(Best) | 1 min after delivery | 
| APGAR score | A= Appearance P=Pulse G=Grimace A=Attitude R=Respiration; 0(Worst)-10(Best) | 5 min after delivery |