Impact of Labor and Delivery on Ultrasound Measured Cricothyroid Membrane Depth and Height

The cricothyroid membrane acts as a route through which the upper airway can be accessed to provide oxygen and ventilation to patients. Anesthesiologists need to deliver oxygen and ventilation to patients under general anesthesia, where patients may lose the ability to breath for themselves. Access through this membrane to provide oxygen and ventilation is critical in emergency situations where other traditional means to access the airway (e.g. through endotracheal ventilation, supraglottic airway devices or face mask ventilation) have failed. It is known, from previous studies, that due to the physiological changes that occur in labour, the upper airway of the body undergoes changes that can make accessing the airway through traditional means more difficult, specifically during the period of labor, delivery, and just after delivery. Ultrasound is becoming increasingly popular due to its ability both to identify the cricothyroid membrane and to improve success in accessing the airway through the cricothyroid membrane. What is not known, and has not been studied to date, is specifically how the anatomy (i.e. its height and its depth) specifically changes during the period of labour, delivery and just after delivery.

The aim of this study would be to scan (using ultrasound) pregnant women's necks once at the very start of their labour, and once within 4 hours of delivery of their baby, to identify how the size and depth of the cricothyroid membrane changes. This information would improve the understanding of how to best approach accessing this membrane in laboring pregnant women.

The investigators hypothesize that in labouring third trimester patient, that the depth to the cricothyroid membrane will increase, and there will be no change in the cricothyroid membrane height.

Study Overview

• Status: Completed
• Conditions: Airway Complication of Anesthesia
• Intervention / Treatment: Device: Ultrasound

• Study Type: Interventional
• Enrollment (Actual): 50
• Phase: Not Applicable

Contacts and Locations

Study Locations

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

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 50 years (Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Age >=18 years old
• Pregnant patients in third trimester (>28/40 weeks)
• Ability to understand the rationale of the study assessments and to provide signed consent.

Exclusion Criteria:

• Neck arthritis
• Cervical stenosis
• Known cervical degenerative disc disease
• Rheumatoid Arthritis
• Any restriction of neck movement
• Upper limb neurology
• Patient refusal
• Patients not in established labour.
• Patients undergoing cesarean section
• Known distorted airway anatomy

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Ultrasound; Ultrasound measurements of the cricothyroid membrane.	Device: Ultrasound; Ultrasound scan of the cricothyroid membrane

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cricothyroid membrane position change	Difference between the depth from the skin to the cricothyroid membrane- tracheal interface change ultrasound between the onset of established labor and following delivery of the baby and placenta.	24 hours

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cricothyroid membrane size change	Difference between the height of the cricothyroid membrane (CTM) at the onset of established labor and the height of CTM following delivery of the baby.	24 hours

Collaborators and Investigators

• Sponsor: Samuel Lunenfeld Research Institute, Mount Sinai Hospital
• Investigators: Principal Investigator: Eric You-Ten, MD, Mount Sinai Hospital

Study record dates

Study Major Dates

• Study Start (Actual): September 1, 2020
• Primary Completion (Actual): November 2, 2022
• Study Completion (Actual): November 2, 2022

Study Registration Dates

• First Submitted: August 28, 2020
• First Submitted That Met QC Criteria: September 10, 2020
• First Posted (Actual): September 11, 2020

Study Record Updates

• Last Update Posted (Actual): March 19, 2024
• Last Update Submitted That Met QC Criteria: March 15, 2024
• Last Verified: March 1, 2024

More Information

Terms related to this study

• Keywords: ultrasound; pregnancy; cricothyroid membrane
• Other Study ID Numbers: 20-01

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