In Vitro Evaluation of Spontaneous and Oxytocin-induced Contractility of Pregnant Human Myometrium During Exposure to Dexmedetomidine

February 24, 2025 updated by: Samuel Lunenfeld Research Institute, Mount Sinai Hospital

Postpartum hemorrhage (PPH) remains to be one of the leading causes of maternal morbidity and mortality. It has been noted that an increasing number of PPH is attributed to the increased incidence of uterine atony. Myometrial contraction is affected by the choice of anesthetic technique and medications during cesarean delivery (CD). It has been proven that exposure to oxytocin during labor results in a decrease in myometrial contractions.

Dexmedetomidine is a drug which has been used in obstetric practice due to its desirable effects such as decreasing pain, reduced elevation in blood pressure and heart rate, sedation, and diminished anesthetic requirement. It has been used as an adjunct during spinal or epidural anesthesia during CD and even during general anesthesia for some obstetric surgeries.

The use of dexmedetomidine has been continuously rising due to its favorable effects. Its use as an adjunct in general anesthesia for obstetrical surgeries has been shown to have promising advantages. During this pandemic, dexmedetomidine has been utilized largely as a sedative in critically ill and intubated patients. This does not exclude critically ill pregnant patients who may also need to deliver urgently. Thus, it is important to investigate its effect on uterine contractility on this particular group of patients.

The investigators hypothesize that dexmedetomidine causes a dose-dependent increase in contractility of the pregnant human myometrium, both spontaneous and oxytocin-induced.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

50

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Canada
    • Ontario
      • Toronto, Ontario, Canada, M5G1X5
        • Mount Sinai Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 50 years (Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Pregnant patients scheduled for elective CD under regional anesthesia at 37-41 weeks of gestational age will be included in this study.
  • Only patients for primary CD or repeat CD (1x) will be included in this study since excessive uterine scarring from multiple CD may affect the contractility of myometrial sample.

Exclusion Criteria:

  • patient refusal
  • emergency CD
  • general anesthesia
  • placenta accreta spectrum disorder
  • any condition predisposing the patient to uterine atony (e.g. polyhydramnios, multiple gestation)
  • patients taking medications affecting myometrial contractions(labetalol, magnesium etc.).

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Dexmedetomidine
The myometrial samples are bathed in increasing concentrations of dexmedetomidine (from 10 -9M to 10 -4M).
Drug: Dexmedetomidine
Dexmedetomidine (10-9M to 10-4M)
Active Comparator: Oxytocin
The myometrial samples are bathed in oxytocin 20nM.
Drug: Oxytocin
Oxytocin solution, 20nM concentration
Other Names:
  • pitocin
Active Comparator: Dexmedetomidine + Oxytocin
The myometrial samples are bathed in oxytocin at 20nM along with dexmedetomidine (10-9M to 10-4M).
Drug: Oxytocin
Oxytocin solution, 20nM concentration
Other Names:
  • pitocin
Drug: Dexmedetomidine
Dexmedetomidine (10-9M to 10-4M)
Active Comparator: Oxytocin pre-treatment followed by Dexmedetomidine
The myometrial samples are pre-treated with oxytocin (10-5M) for 2 hours, and then in increasing concentrations of dexmedetomidine (from 10 -9M to 10 -4M).
Drug: Oxytocin
Oxytocin solution, 20nM concentration
Other Names:
  • pitocin
Drug: Dexmedetomidine
Dexmedetomidine (10-9M to 10-4M)
Active Comparator: Oxytocin pre-treatment followed by Oxytocin
The myometrial samples are pre-treated with oxytocin (10-5M) for 2 hours, and then bathed in oxytocin at 20nM.
Drug: Oxytocin
Oxytocin solution, 20nM concentration
Other Names:
  • pitocin
Active Comparator: Oxytocin pre-treatment followed by Dexmedetomidine + Oxytocin
The myometrial samples are pre-treated with oxytocin (10-5M) for 2 hours, and then bathed in oxytocin at 20nM along with dexmedetomidine (10-9M to 10-4M)
Drug: Oxytocin
Oxytocin solution, 20nM concentration
Other Names:
  • pitocin
Drug: Dexmedetomidine
Dexmedetomidine (10-9M to 10-4M)

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Motility index
Time Frame: 4 hours

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.
4 hours

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Integrated area under response curve (AUC)
Time Frame: 4 hours
4 hours
Amplitude of contraction
Time Frame: 4 hours
The maximum extent of uterine muscle contraction, measured in grams (g). The analysis is undertaken by attaching myometrial strips between an isometric force transducer and the base of an organ bath chamber.
4 hours
Frequency of contraction
Time Frame: 4 hours
The number of contractions in uterine muscle (myometrium) over 10 minutes, spontaneously and in response to an agonist. The analysis is undertaken by attaching myometrial strips between an isometric force transducer and the base of an organ bath chamber.
4 hours

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Samuel Lunenfeld Research Institute, Mount Sinai Hospital

Investigators

  • Principal Investigator: Mrinalini Balki, MD, Mount Sinai Hospital

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

November 2, 2022

Primary Completion (Actual)

November 21, 2024

Study Completion (Actual)

November 22, 2024

Study Registration Dates

First Submitted

August 19, 2022

First Submitted That Met QC Criteria

August 19, 2022

First Posted (Actual)

August 23, 2022

Study Record Updates

Last Update Posted (Actual)

March 25, 2025

Last Update Submitted That Met QC Criteria

February 24, 2025

Last Verified

January 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 22-05

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Subscribe