Comparison of Phenylephrine and Norepinephrine for Spinal-induced Hypotension

Study Overview
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Brief Summary
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Hypotension after spinal anaesthesia for cesarean deliveries is frequently encountered. Phenylephrine an α-agonist is commonly used for the prevention and treatment of spinal-induced hypotension. Phenylephrine causes baroreceptor-mediated bradycardia leading to subsequent reduction in cardiac output. Preservation of heart rate and cardiac output is important in high-risk conditions such as placental insufficiency, fetal distress and maternal cardiac disease. Recently, norepinephrine has been found as effective as phenylephrine in treatment of spinal induced hypotension. When norepinephrine is used as a bolus, it is effective at maintaining blood pressure while also conferring a greater heart rate and cardiac output compared to phenylephrine.

Official Title
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Comparison of Intravenous Phenylephrine and Norepinephrine for Treatment of Spinal-induced Hypotension in Caesarian Deliveries

Conditions
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Spinal Induced-hypotension

Intervention / Treatment
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* Drug: Norepinephrine
* Drug: Phenylephrine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Elective cesarean delivery under spinal anaesthesia ASA PS II Age ≥18 years Singleton pregnancy beyond 37 weeks' gestation Weight between 50 and 100 kg Height between 150 and 180 cm Exclusion Criteria: Patient refusal to participate Allergy or hypersensitivity to Norepinephrine or Phenylephrine Preexisting or pregnancy-induced hypertension Cardiovascular or cerebrovascular disease Fetal abnormalities Use of monoamine oxidase inhibitors or tricyclic antidepressants

Ages Eligible for Study
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Minimum Age: 18 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: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Phenylephrine group<br>Phenylephrine 100mcg was administered manually by the anaesthesiologist every time the SBP was 20% lower than baseline and the HR ≥60 bpm. | Drug: Phenylephrine<br>* Phenylephrine 100mcg was administered manually by the anaesthesiologist every time the SBP was 20% lower than baseline and the HR ≥60 bpm.<br>* Other names: Phenylepherine group;|
| Experimental: Norepinephrine group<br>Norepinephrine 8mcg was administered manually by the anaesthesiologist every time the SBP was 20% lower than baseline and the HR ≥60 bpm. | Drug: Norepinephrine<br>* Norepinephrine 8mcg was administered manually by the anaesthesiologist every time the SBP was 20% lower than baseline and the HR ≥60 bpm.<br>* Other names: Norepinephrine group;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To compare blood pressure between two groups. |  | 6 months | 
| To compare percentage of incidence of hypotension between two groups. |  | 6 months | 
| compare percentage of incidence of bradycardia between the two groups |  | 6 months |