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Defining the Normal Range for Maximal Sniff Diaphragm Thickening Fraction

Completed
Conditions
Diaphragm
Registration Number
NCT03129386
Lead Sponsor
University Health Network, Toronto
Brief Summary

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.

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.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
60
Inclusion Criteria
  • Over 18 years of age
Exclusion Criteria
  • Antecedent history of neuromuscular or cardiorespiratory disease

Study & Design

Study Type
OBSERVATIONAL
Study Design
Not specified
Primary Outcome Measures
NameTimeMethod
Sniff diaphragm thickening fractionDay 1

Thickening of the diaphragm during an inspiratory sniff

Maximal diaphragm thickening fractionDay 1

Thickening of the diaphragm during a maximal inspiratory effort

Resting tidal thickening fractionDay 1

Thickening of the diaphragm during resting tidal breathing

Secondary Outcome Measures
NameTimeMethod

Trial Locations

Locations (1)

University Health Network

🇨🇦

Toronto, Ontario, Canada

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