Norepinephrine To Prevent Hypotension After Spinal Anesthesia For Cesarean Delivery: A Dose Finding Study

Hypotension Clinical Trial

Official title:

Norepinephrine To Prevent Hypotension After Spinal Anesthesia For Cesarean Delivery: A Dose Finding Study

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT02654847
• Other study ID #: 16-02
• Status: Completed
• Phase: N/A
• First received: January 5, 2016
• Last updated: August 29, 2016
• Start date: January 2016
• Est. completion date: April 2016

Study information

• Verified date: August 2016
• Source: Samuel Lunenfeld Research Institute, Mount Sinai Hospital
• Contact: n/a
• Is FDA regulated: No
• Health authority: Canada: Ethics Review Committee
• Study type: Interventional

Clinical Trial Summary

Spinal anesthesia is the most common anesthetic technique for elective Cesarean delivery (CD), but the most frequent unwanted side effect is hypotension, which can cause nausea and vomiting, as well as effects on the fetus. Prevention and treatment of maternal hypotension includes intravenous fluids and vasopressors. Phenylephrine is the most common vasopressor used for this purpose. However, it has been shown to reduce maternal heart rate and cardiac output, which may be a concern in an already compromised fetus. Norepinephrine is commonly used in high concentrations in intensive care and recent studies have suggested that in low concentrations it may be a better alternative to phenylephrine in elective CD, as it does not reduce the maternal heart rate or cardiac output. The optimum bolus dose of norepinephrine to prevent hypotension after spinal anesthesia in elective CD has not been elucidated. The investigators propose this study to determine the dose that would be effective in 90% of patients (ED90).

A previous study by Ngan Kee et al, using continuous infusion of norepinephrine to prevent hypotension in elective CD, suggested a potency ratio for norepinephrine to phenylephrine of approximately 16:1. Hence, the investigators hypothesise that the ED90 will be approximately 6 µg, given that the current phenylephrine bolus dose at the investigators' institution is approximately 100 µg.

Description:

The use of norepinephrine to prevent and treat hypotension during cesarean delivery (CD) is new and data in the literature are scarce. A recent randomised controlled trial by Ngan Kee et al compared continuous infusions of norepinephrine and phenylephrine to prevent hypotension during CD. They showed that norepinephrine was effective at maintaining blood pressure, with a greater cardiac output and heart rate compared to phenylephrine. However, the effective bolus dose of norepinephrine needed to prevent maternal hypotension was not determined, and since this is a relatively new arena, no dose-response studies are available in the literature either. Therefore, it would be logical to establish the effective bolus dose of norepinephrine TO PREVENT HYPOTENSION during elective CD.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 40
• Est. completion date: April 2016
• Est. primary completion date: March 2016
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Female
• Age group: 18 Years to 50 Years

Eligibility

Inclusion Criteria:

• Elective CD under spinal anesthesia

• Normal singleton pregnancy beyond 36 weeks gestation

• ASA physical status II/III

• Weight 50-100 kg, height 150-180 cm

• Age over 18 years

• Informed consent

Exclusion Criteria:

• Patient refusal

• Allergy or hypersensitivity to norepinephrine or sulfite

• Preexisting or pregnancy-induced hypertension

• Cardiovascular or cerebrovascular disease

• Fetal abnormalities

• History of diabetes, excluding gestational diabetes

• Use of monoamine oxidase inhibitors, triptyline or imipramine antidepressants

Study Design

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Caregiver, Investigator), Primary Purpose: Treatment

Related Conditions & MeSH terms

• Hypotension

Intervention

Drug:
• Norepinephrine

• Normal Saline
0.9% sodium chloride solution, used as a diluent.

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	Systolic blood pressure	The primary outcome of this study will be the success/response of the norepinephrine dose to maintain the systolic blood pressure at or above 80% of baseline, from induction of spinal anesthesia to delivery of the fetus.	30 minutes	Yes
Secondary	Presence of Nausea	Presence of nausea in patients from induction of spinal anesthesia to delivery of the fetus.	30 minutes	No
Secondary	Presence of Vomiting	Presence of vomiting in patients from induction of spinal anesthesia to delivery of the fetus.	30 minutes	No
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	Yes
Secondary	Bradycardia: Heart rate less than 50 bpm	Heart rate less than 50 bpm, from induction of spinal anesthesia	30 minutes	Yes
Secondary	Upper sensory level of anesthetic block, assessed by pinprick upon delivery	Upper sensory level of anesthesia, assessed by pinprick upon delivery	30 minutes	No
Secondary	Umbilical artery pH	Umbilical artery pH	24 hours	No
Secondary	Umbilical artery partial pressure of carbon dioxide	Umbilical artery partial pressure of carbon dioxide	24 hours	No
Secondary	Umbilical artery partial pressure of oxygen	Umbilical artery partial pressure of oxygen	24 hours	No
Secondary	Umbilical artery bicarbonate	Umbilical artery bicarbonate	24 hours	No
Secondary	Umbilical artery base excess	Umbilical artery base excess	24 hours	No
Secondary	Umbilical vein pH	Umbilical vein pH	24 hours	No
Secondary	Umbilical vein partial pressure of carbon dioxide	Umbilical vein partial pressure of carbon dioxide	24 hours	No
Secondary	Umbilical vein partial pressure of oxygen	Umbilical vein partial pressure of oxygen	24 hours	No
Secondary	Umbilical vein bicarbonate	Umbilical vein bicarbonate	24 hours	No
Secondary	Umbilical vein base excess	Umbilical vein base excess	24 hours	No