The Effect of Ondansetron on Cardiac Output in Elective Cesarean Deliveries

University of British Columbia

Status and phase: Completed; Phase 2

Conditions: Cardiac Output

Treatments: Other: Normal saline; Drug: Ondansetron

Study type: Interventional

Funder types: Other

Identifiers

NCT01841606

H12-03634

Details and patient eligibility

About

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.

Full description

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.

Enrollment: 57 patients

Sex: Female

Ages: 19+ years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Elective CD under spinal anesthesia
• Fluency in English

Exclusion criteria

• Contraindication to spinal anesthesiA
• Allergy to ondansetron

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Quadruple Blind

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57 participants in 2 patient groups, including a placebo group

Ondansetron

Experimental group

Description:

4mg of IV ondansetron 5 minutes prior to initiation of spinal anesthesia

Treatment:

Drug: Ondansetron

Placebo

Placebo Comparator group

Description:

10mL of IV normal saline 5 minutes prior to initiation of spinal anesthesia

Treatment:

Other: Normal saline