Cardiac Output, Cesarean Section, Hypotension
Conditions
Keywords
transthoracic bioreactance, noninvasive monitoring, vasopressor, blood pressure
Brief summary
During Cesarean delivery, phenylephrine is used to maintain the patient's blood pressure. Low blood pressure is the most common side effect of the spinal medication used to anesthetize the patient prior to the start of surgery. This low blood pressure can also trigger unpleasant side effects such as nausea, vomiting and low Apgar scores for the baby. Currently there are 2 methods of phenylephrine administration during Cesarean section. One method is by intermittent bolus and the other is by continuous infusion. It is ideal to have a regimen for phenylephrine administration that maintains blood pressure without compromising cardiac output. In this study, cardiac output and blood pressure will be measured by transthoracic bioimpedance, which is a new technique of noninvasive continuous cardiac output monitoring. The hypothesis of this study is that the continuous infusion of phenylephrine will be equally effective in maintaining blood pressure as compared to the intermittent injection, and will induce less hemodynamic changes.
Interventions
DRUGPhenylephrine
phenylephrine 120 micrograms/mL, administered either by continuous infusion or by intermittent bolus dose
Sponsors
Samuel Lunenfeld Research Institute, Mount Sinai Hospital
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
FEMALE
Age
18 Years to 50 Years
Healthy volunteers
Yes
Inclusion criteria
* Ability to communicate in English * Elective Cesarean Delivery under spinal anesthesia * Normal singleton pregnancy beyond 36 weeks gestation * ASA physical status I/II * Weight 50-100 kg, height 150-180 cm * Age over 18 years
Exclusion criteria
* Patient refusal * Inability to communicate in English * Allergy or hypersensitivity to phenylephrine * Preexisting or pregnancy-induced hypertension * Cardiovascular or cerebrovascular disease * Fetal abnormalities * History of diabetes, excluding gestational diabetes * Contra-indications for spinal anesthesia
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| The maximum decrease in cardiac output in the pre-delivery period. | 30 minutes |
Secondary
| Measure | Time frame |
|---|---|
| Incidence of hypotension in the pre-delivery period (BP < 80% baseline) | 30 minutes |
| Incidence of hypertension in the pre-delivery period (BP > 120% baseline) | 30 minutes |
| Maximum decrease in heart rate in the pre-delivery period. | 30 minutes |
| Total dose of phenylephrine in the pre-delivery period | 30 minutes |
| Umbilical artery and vein blood gases | 24 hours |
| Incidence of nausea and vomiting in the pre-delivery period | 30 minutes |
Countries
Canada
Outcome results
None listed