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Effects of Ephedrine, Phenylephrine, Norepinephrine and Vasopressin on Contractility of Human Myometrium and Umbilical Vessels: An In-vitro Study

Primary Purpose

Hypotension

Status
Recruiting
Phase
Not Applicable
Locations
Canada
Study Type
Interventional
Intervention
Ephedrine
Phenylephrine
Norepinephrine
Vasopressin
Sponsored by
Samuel Lunenfeld Research Institute, Mount Sinai Hospital
About
Eligibility
Locations
Arms
Outcomes
Full info

About this trial

This is an interventional treatment trial for Hypotension focused on measuring vasopressor, ephedrine, phenylephrine, norepinephrine, umbilical arteries, uterine contraction, fetal acidosis, vasopressin

Eligibility Criteria

19 Years - 40 Years (Adult)FemaleAccepts Healthy Volunteers

Inclusion Criteria:

  • Patients who give written consent to participate in this study
  • Patients with gestational age 37-41 weeks
  • Patients of 19-40 years
  • Non-laboring patients, not exposed to exogenous oxytocin
  • Patients requiring elective primary or first repeat caesarean delivery
  • Patients undergoing caesarean delivery under spinal anesthesia

Exclusion Criteria:

  • Patients who refuse to give written informed consent
  • Patients who require general anesthesia
  • Patients in labor and those receiving oxytocin for induction of labor
  • Emergency caesarean delivery in labor
  • Patients who have had previous uterine surgery or >1 previous caesarean delivery
  • Patients with any condition predisposing to uterine atony
  • Patients on medications that could affect myometrial contractility, such as insulin, nifedipine, labetolol or magnesium sulfate.

Sites / Locations

  • Mount Sinai HospitalRecruiting

Arms of the Study

Arm 1

Arm 2

Arm 3

Arm 4

Arm 5

Arm 6

Arm 7

Arm 8

Arm 9

Arm 10

Arm 11

Arm 12

Arm Type

Experimental

Experimental

Experimental

Experimental

Experimental

Experimental

Experimental

Experimental

Experimental

Experimental

Experimental

Experimental

Arm Label

Myometrium + Ephedrine

Myometrium + Phenylephrine

Myometrium + Norepinephrine

Myometrium + Vasopressin

Umbilical artery + Ephedrine

Umbilical artery + Phenylephrine

Umbilical artery + Norepinephrine

Umbilical artery + Vasopressin

Umbilical vein + Ephedrine

Umbilical vein + Phenylephrine

Umbilical vein + Norepinephrine

Umbilical vein + Vasopressin

Arm Description

The myometrial samples are bathed in physiological salt solution (PSS) with increasing concentrations of ephedrine

The myometrial samples are bathed in physiological salt solution (PSS) with increasing concentrations of phenylephrine

The myometrial samples are bathed in physiological salt solution (PSS) with increasing concentrations of norepinephrine

The myometrial samples are bathed in physiological salt solution (PSS) with increasing concentrations of vasopressin

The umbilical artery samples are bathed in physiological salt solution (PSS) with increasing concentrations of ephedrine

The umbilical artery samples are bathed in physiological salt solution (PSS) with increasing concentrations of phenylephrine

The umbilical artery samples are bathed in physiological salt solution (PSS) with increasing concentrations of norepinephrine

The umbilical artery samples are bathed in physiological salt solution (PSS) with increasing concentrations of vasopressin

The umbilical vein samples are bathed in physiological salt solution (PSS) with increasing concentrations of ephedrine

The umbilical vein samples are bathed in physiological salt solution (PSS) with increasing concentrations of phenylephrine

The umbilical vein samples are bathed in physiological salt solution (PSS) with increasing concentrations of norepinephrine

The umbilical vein samples are bathed in physiological salt solution (PSS) with increasing concentrations of vasopressin

Outcomes

Primary Outcome Measures

Motility index
Motility index (MI) is a calculated outcome, based on the formula: frequency/(10 x amplitude). Frequency and amplitude are secondary outcome measures as described below. The analysis is undertaken by attaching myometrial strips between an isometric force transducer and the base of an organ bath chamber.

Secondary Outcome Measures

Amplitude of contraction
The maximum extent of uterine muscle and umbilical vessel contractions, measured in grams (g). The analysis is undertaken by attaching myometrial strips and umbilical vessel rings between an isometric force transducer and the base of an organ bath chamber.
Frequency of contraction
The number of contractions in uterine muscle (myometrium) and umbilical vessel rings over 10 minutes, spontaneously and in response to an agonist. The analysis is undertaken by attaching myometrial strips and umbilical vessel rings between an isometric force transducer and the base of an organ bath chamber.
Integrated area under response curve (AUC)

Full Information

First Posted
August 8, 2019
Last Updated
October 24, 2022
Sponsor
Samuel Lunenfeld Research Institute, Mount Sinai Hospital
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1. Study Identification

Unique Protocol Identification Number
NCT04053478
Brief Title
Effects of Ephedrine, Phenylephrine, Norepinephrine and Vasopressin on Contractility of Human Myometrium and Umbilical Vessels: An In-vitro Study
Official Title
Effects of Ephedrine, Phenylephrine, Norepinephrine and Vasopressin on Contractility of Human Myometrium and Umbilical Vessels: An In-vitro Study
Study Type
Interventional

2. Study Status

Record Verification Date
October 2022
Overall Recruitment Status
Recruiting
Study Start Date
July 8, 2019 (Actual)
Primary Completion Date
December 2024 (Anticipated)
Study Completion Date
December 2024 (Anticipated)

3. Sponsor/Collaborators

Responsible Party, by Official Title
Sponsor
Name of the Sponsor
Samuel Lunenfeld Research Institute, Mount Sinai Hospital

4. Oversight

Studies a U.S. FDA-regulated Drug Product
No
Studies a U.S. FDA-regulated Device Product
No
Data Monitoring Committee
No

5. Study Description

Brief Summary
Hypotension is one of the most common adverse effects of spinal anesthesia for cesarean deliveries, affecting as many as 55-90% of mothers. Hypotension during cesarean deliveries can have detrimental effects on the mother and neonate. Various vasopressors, such as ephedrine, phenylephrine and more recently norepinephrine, have been used for the prevention and treatment of hypotension at cesarean deliveries. Ephedrine was historically considered as the gold standard vasopressor for the management of hypotension during cesarean deliveries. This was based on studies in animal models that showed preserved uteroplacental circulation with ephedrine and not with phenylephrine. However, multiple studies in the past several decades have shown that phenylephrine compared with ephedrine results in a more favorable fetal acid-base status. Consequently, the use of phenylephrine for blood pressure management during cesarean deliveries increased. Recently, norepinephrine was introduced in the obstetrical practice for the management of hypotension at cesarean deliveries, due to its ability to maintain maternal cardiac output better than phenylephrine. Studies have also investigated the use of vasopressin to limit hypotension during CD. There have been case reports of successful vasopressin usage to treat post-spinal hypotension after CD in patients with advanced idiopathic pulmonary arterial hypertension as well as severe mitral stenosis with pulmonary hypertension. Its effect was associated with hemodynamic stability without evidence of harm to the mother or child. However, much controversy still exists surrounding the choice of vasopressor in the obstetric population, in large part due to their varying efficacies, and maternal and fetal effects. Vasopressors used for the treatment of hypotension during cesarean deliveries can have significant direct or indirect effects on the perfusion of uteroplacental and umbilical vessels. Reduction of uteroplacental perfusion and constriction of umbilical vessels can result in fetal acidosis, however, the mechanisms for these effects are unclear. The investigators hypothesize that ephedrine, phenylephrine and norepinephrine and vasopressin have variable effects on the contractility of pregnant myometrium and umbilical arteries due to their variable actions on adrenergic alpha (α) and beta (β) receptors, as well as vasopressin1 and vasopressin2 receptors located in these tissues.
Detailed Description
One of the major concerns addressed in the literature is the risk of fetal acidosis related to the use of vasopressors, which varies according to the type of drug used. Since severe fetal acidosis is associated with a two- and four-fold increase in neonatal morbidity and mortality, respectively, it is important to understand the mechanism by which these medications may contribute to fetal acidosis. It is well known that reduced uteroplacental blood flow can result in impaired fetal oxygenation and fetal acidosis. This can occur indirectly via compression of vessels due to myometrial contractions or directly by vasoactive effects on umbilical vessels. So far, no studies have directly explored the role of the aforementioned vasopressors on myometrial contractions and umbilical vessel vasoconstriction. An in-vitro approach in isolated tissues will eliminate many clinical confounding variables, allowing direct comparison of the drugs in a controlled environment, and providing insight into the contractile mechanisms responsible for their neonatal effects. There is currently no consensus as to which vasopressor is best for the management of hypotension in obstetric patients and the mitigation of fetal acidosis. A survey of the members of the Society of Obstetric Anesthesia and Perinatology suggested significant variation in the practice of vasopressor use during cesarean deliveries. The evidence from animal studies contradicts the effects seen in human studies. This is possibly related to species differences in adrenergic receptor distribution, affinity to vasopressors, or placental transfer of vasopressors. It is well known that reduced uteroplacental blood flow can result in impaired fetal oxygenation and fetal acidosis. This can occur indirectly via compression of vessels due to myometrial contractions or directly by vasoactive effects on umbilical arteries. However, none of the studies so far have directly explored the role of the aforementioned vasopressors on myometrial contractions and umbilical artery vasoconstriction. An in-vitro approach in isolated tissues will eliminate many clinical confounding variables, allowing direct comparison of the drugs in a controlled environment, and providing insight into the contractile mechanisms responsible for their neonatal effects.

6. Conditions and Keywords

Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Hypotension
Keywords
vasopressor, ephedrine, phenylephrine, norepinephrine, umbilical arteries, uterine contraction, fetal acidosis, vasopressin

7. Study Design

Primary Purpose
Treatment
Study Phase
Not Applicable
Interventional Study Model
Parallel Assignment
Masking
None (Open Label)
Allocation
Non-Randomized
Enrollment
144 (Anticipated)

8. Arms, Groups, and Interventions

Arm Title
Myometrium + Ephedrine
Arm Type
Experimental
Arm Description
The myometrial samples are bathed in physiological salt solution (PSS) with increasing concentrations of ephedrine
Arm Title
Myometrium + Phenylephrine
Arm Type
Experimental
Arm Description
The myometrial samples are bathed in physiological salt solution (PSS) with increasing concentrations of phenylephrine
Arm Title
Myometrium + Norepinephrine
Arm Type
Experimental
Arm Description
The myometrial samples are bathed in physiological salt solution (PSS) with increasing concentrations of norepinephrine
Arm Title
Myometrium + Vasopressin
Arm Type
Experimental
Arm Description
The myometrial samples are bathed in physiological salt solution (PSS) with increasing concentrations of vasopressin
Arm Title
Umbilical artery + Ephedrine
Arm Type
Experimental
Arm Description
The umbilical artery samples are bathed in physiological salt solution (PSS) with increasing concentrations of ephedrine
Arm Title
Umbilical artery + Phenylephrine
Arm Type
Experimental
Arm Description
The umbilical artery samples are bathed in physiological salt solution (PSS) with increasing concentrations of phenylephrine
Arm Title
Umbilical artery + Norepinephrine
Arm Type
Experimental
Arm Description
The umbilical artery samples are bathed in physiological salt solution (PSS) with increasing concentrations of norepinephrine
Arm Title
Umbilical artery + Vasopressin
Arm Type
Experimental
Arm Description
The umbilical artery samples are bathed in physiological salt solution (PSS) with increasing concentrations of vasopressin
Arm Title
Umbilical vein + Ephedrine
Arm Type
Experimental
Arm Description
The umbilical vein samples are bathed in physiological salt solution (PSS) with increasing concentrations of ephedrine
Arm Title
Umbilical vein + Phenylephrine
Arm Type
Experimental
Arm Description
The umbilical vein samples are bathed in physiological salt solution (PSS) with increasing concentrations of phenylephrine
Arm Title
Umbilical vein + Norepinephrine
Arm Type
Experimental
Arm Description
The umbilical vein samples are bathed in physiological salt solution (PSS) with increasing concentrations of norepinephrine
Arm Title
Umbilical vein + Vasopressin
Arm Type
Experimental
Arm Description
The umbilical vein samples are bathed in physiological salt solution (PSS) with increasing concentrations of vasopressin
Intervention Type
Drug
Intervention Name(s)
Ephedrine
Intervention Description
Ephedrine in solution, at applicable concentrations based on literature
Intervention Type
Drug
Intervention Name(s)
Phenylephrine
Intervention Description
Phenylephrine, at applicable concentrations based on literature
Intervention Type
Drug
Intervention Name(s)
Norepinephrine
Intervention Description
Norepinephrine, at applicable concentrations based on literature
Intervention Type
Drug
Intervention Name(s)
Vasopressin
Intervention Description
Vasopressin, at applicable concentrations based on literature
Primary Outcome Measure Information:
Title
Motility index
Description
Motility index (MI) is a calculated outcome, based on the formula: frequency/(10 x amplitude). Frequency and amplitude are secondary outcome measures as described below. The analysis is undertaken by attaching myometrial strips between an isometric force transducer and the base of an organ bath chamber.
Time Frame
4 hours
Secondary Outcome Measure Information:
Title
Amplitude of contraction
Description
The maximum extent of uterine muscle and umbilical vessel contractions, measured in grams (g). The analysis is undertaken by attaching myometrial strips and umbilical vessel rings between an isometric force transducer and the base of an organ bath chamber.
Time Frame
4 hours
Title
Frequency of contraction
Description
The number of contractions in uterine muscle (myometrium) and umbilical vessel rings over 10 minutes, spontaneously and in response to an agonist. The analysis is undertaken by attaching myometrial strips and umbilical vessel rings between an isometric force transducer and the base of an organ bath chamber.
Time Frame
4 hours
Title
Integrated area under response curve (AUC)
Time Frame
4 hours

10. Eligibility

Sex
Female
Minimum Age & Unit of Time
19 Years
Maximum Age & Unit of Time
40 Years
Accepts Healthy Volunteers
Accepts Healthy Volunteers
Eligibility Criteria
Inclusion Criteria: Patients who give written consent to participate in this study Patients with gestational age 37-41 weeks Patients of 19-40 years Non-laboring patients, not exposed to exogenous oxytocin Patients requiring elective primary or first repeat caesarean delivery Patients undergoing caesarean delivery under spinal anesthesia Exclusion Criteria: Patients who refuse to give written informed consent Patients who require general anesthesia Patients in labor and those receiving oxytocin for induction of labor Emergency caesarean delivery in labor Patients who have had previous uterine surgery or >1 previous caesarean delivery Patients with any condition predisposing to uterine atony Patients on medications that could affect myometrial contractility, such as insulin, nifedipine, labetolol or magnesium sulfate.
Central Contact Person:
First Name & Middle Initial & Last Name or Official Title & Degree
Mrinalini Balki, MD
Phone
416-586-4800
Ext
5270
Email
mrinalini.balki@uhn.ca
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
Mrinalini Balki, MD
Organizational Affiliation
MOUNT SINAI HOSPITAL
Official's Role
Principal Investigator
Facility Information:
Facility Name
Mount Sinai Hospital
City
Toronto
State/Province
Ontario
ZIP/Postal Code
M5G1X5
Country
Canada
Individual Site Status
Recruiting
Facility Contact:
First Name & Middle Initial & Last Name & Degree
Mrinalini Balki, MD
Phone
416-586-4800
Ext
5270
Email
mrinalini.balki@uhn.ca
First Name & Middle Initial & Last Name & Degree
Alice Luca, MSc
First Name & Middle Initial & Last Name & Degree
Jose Carvalho, MD
First Name & Middle Initial & Last Name & Degree
John Kingdom, MD
First Name & Middle Initial & Last Name & Degree
Chinaza Egbuta, PhD

12. IPD Sharing Statement

Plan to Share IPD
No

Learn more about this trial

Effects of Ephedrine, Phenylephrine, Norepinephrine and Vasopressin on Contractility of Human Myometrium and Umbilical Vessels: An In-vitro Study

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