A Comparison of Intermittent Intravenous Boluses of Phenylephrine and Norepinephrine to Prevent Spinal-induced Hypotension in Cesarean Deliveries

Hypotension Clinical Trial

Official title:

A Comparison of Intermittent Intravenous Boluses of Phenylephrine and Norepinephrine to Prevent Spinal-induced Hypotension in Cesarean Deliveries: a Randomized Controlled Study

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT02962986
• Other study ID #: 16-07
• Status: Completed
• Phase: N/A
• First received: November 7, 2016
• Last updated: May 23, 2017
• Start date: January 2017
• Est. completion date: April 2017

Study information

• Verified date: May 2017
• Source: Samuel Lunenfeld Research Institute, Mount Sinai Hospital
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

Hypotension is a very common complication of spinal anesthesia for cesarean delivery, and can have unwanted side effects on both mother and fetus if not treated promptly. Phenylephrine has been the drug of choice to treat this spinal-induced hypotension. Although phenylephrine is safe to use for this indication, it has been associated with reflex bradycardia and a reduction in cardiac output.

Norepinephrine is a potent vasopressor used to treat hypotension in the critical care setting. Recent studies have looked at norepinephrine's use in the obstetric setting, and have shown that it can be used safely and also has favourable hemodynamic properties when compared to phenylephrine, with less bradycardia and less depression of cardiac output.

The investigators recently conducted a study to determine the ED90 of norepinephrine, and now plan to compare bolus doses of phenylephrine to norepinephrine for treating hypotension following spinal anesthesia for cesarean section.

The investigators hypothesize that norepinephrine, when given as a bolus to prevent post spinal hypotension, will result in around 70% relative decrease in the rate of bradycardia when compared to phenylephrine in patients undergoing elective cesarean delivery under spinal anesthesia.

Description:

Norepinephrine is a potent vasopressor used to treat hypotension in the critical care setting. Recent studies have looked at norepinephrine's use in the obstetric setting, and have shown that it can be used safely and also has favourable hemodynamic properties when compared to phenylephrine, with less bradycardia and less depression of cardiac output. These studies have been limited to using norepinephrine as an infusion and there is limited data with it being used as a bolus to prevent hypotension. A recent study was undertaken at Mount Sinai hospital to determine the ED90 of norepinephrine to treat post spinal hypotension. Secondary outcome data from this trial showed that the incidence of bradycardia associated with this treatment is approximately 7.5%, several times less when compared to the reported 30% with phenylephrine. It would therefore be prudent at this stage to undertake a randomized trial comparing the hemodynamic profile of phenylephrine (our standard practice) and norepinephrine used as intermittent boluses to prevent hypotension and avoid decrease in heart rate during cesarean delivery.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 112
• Est. completion date: April 2017
• Est. primary completion date: April 2017
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Female
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• Informed consent

• Elective CS under spinal anesthesia

• Normal singleton pregnancy beyond 36 weeks gestation

• ASA physical status 2-3

• Current (pregnant) 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

• Allergy or hypersensitivity to sulfite

• Use of monoamine oxidase inhibitors, triptyline or imipramine antidepressants

• Untreated hyperthyroid patients

Related Conditions & MeSH terms

• Hypotension

Intervention

Drug:
• Norepinephrine
Norepinephrine diluted in 5% dextrose solution to a concentration of 6mcg/mL
• Phenylephrine
Phenylephrine diluted in 0.9% normal saline solution to a concentration of 100mcg/mL

Locations

Country	Name	City	State
Canada	Mount Sinai Hospital	Toronto	Ontario

Sponsors (1)

Lead Sponsor	Collaborator
Samuel Lunenfeld Research Institute, Mount Sinai Hospital

Country where clinical trial is conducted

Canada, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Bradycardia: Heart rate less than 50 bpm	Heart rate less than 50 bpm, from induction of spinal anesthesia	30 minutes
Secondary	Hypotension: Systolic blood pressure less than 80% of baseline	Systolic blood pressure below 80% of baseline, from induction of spinal anesthesia to delivery of the fetus.	30 minutes
Secondary	Number of hypotensive episodes	The number of times the systolic blood pressure measures below 80% of baseline, from induction of spinal anesthesia to delivery of the fetus.	30 minutes
Secondary	Hypertension: Systolic blood pressure at or above 120% of baseline	Systolic blood pressure at or above 120% of baseline, from induction of spinal anesthesia to delivery of the fetus.	30 minutes
Secondary	Tachycardia: Heart rate greater than 30% of baseline	Heart rate greater than 30%, from induction of spinal anesthesia to delivery of the fetus.	30 minutes
Secondary	Presence of nausea	Presence of nausea in patients from induction of spinal anesthesia to delivery of the fetus.	30 minutes
Secondary	Number of episodes of nausea	The number of episodes of nausea experienced by patients from induction of spinal anesthesia to delivery of the fetus.	30 minutes
Secondary	Presence of vomiting	Presence of vomiting in patients from induction of spinal anesthesia to delivery of the fetus.	30 minutes
Secondary	Number of episodes of vomiting	The number of episodes of vomiting experienced by patients from induction of spinal anesthesia to delivery of the fetus.	30 minutes
Secondary	Total dose of study drug given	Total dose of study drug given from induction of spinal anesthesia to delivery of the fetus.	30 minutes
Secondary	Apgar scores	The Apgar scores of the infant at 1 and 5 minutes post delivery.	1 minute and 5 minutes
Secondary	Umbilical artery pH	Umbilical artery pH	24 hours
Secondary	Umbilical artery partial pressure of carbon dioxide	Umbilical artery partial pressure of carbon dioxide	24 hours
Secondary	Umbilical artery partial pressure of oxygen	Umbilical artery partial pressure of oxygen	24 hours
Secondary	Umbilical artery bicarbonate (mmol/L)	Umbilical artery bicarbonate	24 hours
Secondary	Umbilical artery base excess (mmol/L)	Umbilical artery base excess	24 hours
Secondary	Umbilical vein pH	Umbilical vein pH	24 hours
Secondary	Umbilical vein partial pressure of carbon dioxide	Umbilical vein partial pressure of carbon dioxide	24 hours
Secondary	Umbilical vein partial pressure of oxygen	Umbilical vein partial pressure of oxygen	24 hours
Secondary	Umbilical vein bicarbonate (mmol/L)	Umbilical vein bicarbonate	24 hours
Secondary	Umbilical vein base excess (mmol/L)	Umbilical vein base excess	24 hours