Defining the Normal Range for Maximal Sniff Diaphragm Thickening Fraction (SNIFF II)

This study is investigating the normal range of maximal diaphragm thickness during a sniff inspiratory manoeuvre using ultrasound in healthy subjects stratified by age and gender.

Study Overview

• Status: Completed
• Conditions: Diaphragm

Detailed Description

Diaphragm dysfunction is associated with poor clinical outcomes in critically ill patients but is difficult to diagnose. Traditionally, diaphragm function is measured by evaluating inspiratory muscle strength via maximal inspiratory pressure (MIP). However, this technique relies on a volitional maximal effort and can be challenging for patients to perform.

An alternative to measuring inspiratory muscle strength is the sniff inspiratory pressure approach. During short, sharp sniffs, the diaphragm is maximally activated.

Currently, there are no reported values of the normal range of maximal diaphragm thickness during a sniff maneuver. This study will define the normal range of values for sniff maximal diaphragm thickening fraction, maximal thickening against an occluded airway, and diaphragm thickening during resting tidal breathing in healthy subjects.

• Study Type: Observational
• Enrollment (Actual): 60

Contacts and Locations

Study Locations

• Canada
  • Ontario
    • Toronto, Ontario, Canada, M5G 2N2
      • University Health Network

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Healthy adult subjects with no antecedent history of neuromuscular or cardiorespiratory disease.

Description

Inclusion Criteria:

• Over 18 years of age

Exclusion Criteria:

• Antecedent history of neuromuscular or cardiorespiratory disease

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Prospective

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Sniff diaphragm thickening fraction	Thickening of the diaphragm during an inspiratory sniff	Day 1
Maximal diaphragm thickening fraction	Thickening of the diaphragm during a maximal inspiratory effort	Day 1
Resting tidal thickening fraction	Thickening of the diaphragm during resting tidal breathing	Day 1

Collaborators and Investigators

• Sponsor: University Health Network, Toronto

Study record dates

Study Major Dates

• Study Start (Actual): June 8, 2016
• Primary Completion (Actual): December 1, 2018
• Study Completion (Actual): January 1, 2019

Study Registration Dates

• First Submitted: April 4, 2017
• First Submitted That Met QC Criteria: April 21, 2017
• First Posted (Actual): April 26, 2017

Study Record Updates

• Last Update Posted (Actual): April 16, 2019
• Last Update Submitted That Met QC Criteria: April 15, 2019
• Last Verified: April 1, 2019

More Information

Terms related to this study

• Other Study ID Numbers: 15-8998-AE

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No
• IPD Plan Description: Currently, there is no plan to make data IPD available to others.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No