The Effect of Ondansetron on Cardiac Output in Elective Cesarean Deliveries

Study Overview
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Brief Summary
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Ondansetron is a medication routinely given to mothers having cesarean deliveries to help prevent and treat nausea and vomiting. The investigators are studying the hemodynamic effects of prophylactic ondansetron on parturients undergoing elective cesarean deliveries under spinal anesthesia.

Detailed Description
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Spinal anesthesia is a routine anesthetic technique for elective cesarean deliveries. Although this provides safe and effective surgical anesthesia, it is not without side effects, including both hypotension and bradycardia. The incidence of hypotension following spinal anesthesia has been estimated to be as high as 80% in an obstetric population. A number of factors are also likely involved in the development of hypotension and bradycardia, including the Bezold-Jarisch Reflex (BJR). Two human studies with spinal anesthesia, one in an obstetric population, have demonstrated ondansetron's ability to presumably attenuate the BJR and better prevent hypotension by antagonism of 5-HT3 receptors. Maintenance of blood pressure and heart rate are vitally important, as they are required for adequate perfusion of the fetus prior to delivery. The investigators plan to investigate the hemodynamic effects of prophylactic ondansetron on parturients undergoing elective cesarean deliveries under spinal anesthesia. Ondansetron is classified as a Pregnancy Category B drug by the FDA, meaning that no adverse fetal effects have been demonstrated in animal studies, but that there is a lack of well controlled studies in pregnant humans.

Official Title
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The Effect of Ondansetron on Cardiac Output in Elective Cesarean Deliveries Under Spinal Anesthesia: A Randomized Controlled Trial

Conditions
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Cardiac Output

Intervention / Treatment
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* Drug: Ondansetron
* Other: Normal saline


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Elective CD under spinal anesthesia Fluency in English Exclusion Criteria: Contraindication to spinal anesthesiA Allergy to ondansetron

Ages Eligible for Study
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Minimum Age: 19 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 |
| --- | --- |
| Experimental: Ondansetron<br>4mg of IV ondansetron 5 minutes prior to initiation of spinal anesthesia | Drug: Ondansetron<br>* 4mg of IV ondansetron<br>* Other names: Zofran;|
| Placebo Comparator: Placebo<br>10mL of IV normal saline 5 minutes prior to initiation of spinal anesthesia | Other: Normal saline<br>* 10mL of IV normal saline<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Cardiac Output From Baseline to 20 Minutes Post-spinal | Maximum change in cardiac output from initiation of spinal anesthesia (baseline) until uterine incision (20 minutes post-spinal) | Baseline and 20 minutes | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Spinal anesthesia, Elective cesarean deliveries, Ondansetron