Effect of Three Weight-adjusted Vasopressors for Elective Cesarean Delivery

Study Overview
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Brief Summary
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This study compared the effects of prophylactic infusion of metaraminol, phenylephrine and norepinephrine adjusted according to body weight on fetal acid-base balance and maternal hemodynamics.

Detailed Description
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At present, the ED90 of metaraminol, phenylephrine, and norepinephrine in the prevention of cesarean section hypotension has been explored. We compare the effects of three drugs on the fetus and mothers at the concentration of ED90 to provide advice on the use of vasoactive drugs for obstetrics anesthesia .

Official Title
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Effect of Three Weight-adjusted Vasopressors for With Combined Spinal-Epidural Anesthesia for Elective Cesarean Delivery: A Randomized Controlled Trial

Conditions
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Cesarean Section Complications

Intervention / Treatment
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* Drug: metaraminol
* Drug: Phenylephrine
* Drug: Norepinephrine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Singleton pregnancy at term scheduled to be delivered via elective cesarean delivery; height 150-180 cm; American Society of Anesthesiologists (ASA) physical status II-III; body mass index (BMI) <35 kg/m2. Exclusion Criteria: transverse presentation, fetal macrosomia; uterine abnormalities (eg, large fibroids, bicornuate uterus); polyhydramnios; ruptured membranes, oligohydramnios; intrauterine growth restriction; gestational or nongestational hypertension, diabetes, or eclampsia; hypertensive disorders or any condition associated with autonomic neuropathy (such as diabetes mellitus for >10 years) or renal failure; contraindications for combined spinal-epidural anesthesia; participants who declined to sign informed consent forms.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 40 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: metaraminol group<br>During the cesarean section, metaraminol 2ug/kg/min is preventively infused after anesthesia to prevent and treat hypotension. | Drug: metaraminol<br>* Infusion of metaraminol adjusted according to body weight to obtain higher pH value of fetal umbilical artery blood.<br>* Other names: M group;|
| Experimental: phenylephrine group<br>During cesarean section, preventive infusion of phenylephrine 0.54ug/kg/min after anesthesia to prevent and treat hypotension. | Drug: Phenylephrine<br>* Infusion of Phenylephrine adjusted according to body weight to obtain higher pH value of fetal umbilical artery blood.<br>* Other names: P group;|
| Experimental: norepinephrine group<br>During cesarean section, preventive infusion of norepinephrine 0.08ug/kg/min after anesthesia to prevent and treat hypotension. | Drug: Norepinephrine<br>* Infusion of Norepinephrine adjusted according to body weight to obtain higher pH value of fetal umbilical artery blood.<br>* Other names: N group;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Umbilical artery blood pH | pH value of fetal umbilical artery blood | 30 seconds after delivery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| hypotension | Number of Participants with systolic blood pressure reduction >20% baseline value or systolic blood pressure <90 mm Hg before delivery | Intraoperative | 
| bradycardia | Number of Participants with heart rate was ≤50 bpm before delivery | Intraoperative | 
| The incidence of nausea in pregnant women | Anesthesiologist observes combined patient dictation. | Intraoperative | 
| Umbilical artery blood base excess | base excess of fetal umbilical artery blood | 30sec after delivery | 
| The incidence of vomiting in pregnant women | Anesthesiologist observes combined patient dictation | Intraoperative |