Cardiac Output
Conditions
Keywords
Spinal anesthesia, Elective cesarean deliveries, Ondansetron
Brief summary
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
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.
Interventions
DRUGOndansetron
4mg of IV ondansetron
OTHERNormal saline
10mL of IV normal saline
Sponsors
University of British Columbia
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
FEMALE
Age
19 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
* Elective CD under spinal anesthesia * Fluency in English
Exclusion criteria
* Contraindication to spinal anesthesiA * Allergy to ondansetron
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in Cardiac Output From Baseline to 20 Minutes Post-spinal | Baseline and 20 minutes | Maximum change in cardiac output from initiation of spinal anesthesia (baseline) until uterine incision (20 minutes post-spinal) |
Countries
Canada
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Ondansetron 4mg IV Ondansetron | 25 |
| Placebo 10mL IV normal saline | 27 |
| Total | 52 |
Baseline characteristics
| Characteristic | Ondansetron | Placebo | Total |
|---|---|---|---|
| Age, Continuous | 34.32 years STANDARD_DEVIATION 3.86 | 34.7 years STANDARD_DEVIATION 4.76 | 34.5 years STANDARD_DEVIATION 4.27 |
| Region of Enrollment Canada | 25 participants | 27 participants | 52 participants |
| Sex: Female, Male Female | 25 Participants | 27 Participants | 52 Participants |
| Sex: Female, Male Male | 0 Participants | 0 Participants | 0 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — |
| other Total, other adverse events | 0 / 25 | 0 / 27 |
| serious Total, serious adverse events | 0 / 25 | 0 / 27 |
Outcome results
Primary
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)
Time frame: Baseline and 20 minutes
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Ondansetron | Change in Cardiac Output From Baseline to 20 Minutes Post-spinal | -2.05 L/min | Standard Deviation 1.43 |
| Placebo | Change in Cardiac Output From Baseline to 20 Minutes Post-spinal | -1.92 L/min | Standard Deviation 1.41 |