Clinical trial NCT00996190: Best Regimen for Phenylephrine Administration During Cesarean Section
Official title: Study to Determine the Best Regimen for Administration of Phenylephrine During Spinal Anesthesia for Cesarean Delivery, as Determined by Maternal Blood Pressure and Cardiac Output
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE4
Conditions: Cesarean Section
Cardiac Output
Hypotension
Keywords: transthoracic bioreactance
noninvasive monitoring
vasopressor
blood pressure
Lead sponsor: Samuel Lunenfeld Research Institute, Mount Sinai Hospital
Sponsor class: OTHER
First posted: 2009-10-16
Enrollment: 60
Sex: FEMALE
Minimum age (years): 18
Maximum age (years): 50
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

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.


Eligibility criteria: 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

Primary outcomes:
measure: The maximum decrease in cardiac output in the pre-delivery period.
timeFrame: 30 minutes
Secondary outcomes:
measure: Maximum decrease in heart rate in the pre-delivery period.
timeFrame: 30 minutes
measure: Incidence of hypotension in the pre-delivery period (BP < 80% baseline)
timeFrame: 30 minutes
measure: Incidence of hypertension in the pre-delivery period (BP > 120% baseline)
timeFrame: 30 minutes
measure: Incidence of nausea and vomiting in the pre-delivery period
timeFrame: 30 minutes
measure: Total dose of phenylephrine in the pre-delivery period
timeFrame: 30 minutes
measure: Umbilical artery and vein blood gases
timeFrame: 24 hours
Other outcomes:
Locations:
city: Toronto
country: Canada
facility: Mount Sinai Hospital
state: Ontario
Study officials:
affiliation: MOUNT SINAI HOSPITAL
name: Jose Carvalho, MD
role: PRINCIPAL_INVESTIGATOR
References: