Diaphragm IssuesReDU analysisNCT07747532
Reliability of Diaphragm Ultrasound: Intra- and Interrater Analysis
An observational study of Diaphragm Issues, run by University Health Network, Toronto at 1 site in Canada.
Trial summary
It is often difficult for anesthesiologists to select an ultrasound method that will give consistent results and also be a reliable way to examine the diaphragm, especially on the left side of the chest. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Diaphragm Issues
- How many people
- 58 participants
- Where
- 1 siteCanada
- Study dates
- Aug 2026to Jul 2028
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Patient aged 18 years or over who are scheduled for any elective surgical procedure at Toronto Western Hospital or Women's College Hospital, Toronto.
Who may be able to join
- Participants must meet all the following inclusion criteria to be eligible for the study:
- Any elective surgical patient
- Age ≥18 years
- American Society of Anesthesiologists class I to III
Who cannot join
- Participants will not be eligible for the study if any of the exclusion criteria is present:
- Pregnancy - patients will be asked if they are pregnant or not and screened post-consent from their medical chart.
- History of diaphragmatic dysfunction
- Previous surgical procedures on the lung, thorax or diaphragm.
- Inability to understand the study activities and provide informed consent when explained about the study and the consent process
- Refusal to participate in study
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Canada1 site
Toronto Western Hospital, University Health Network
Toronto, Ontario, M5T 2S8
About this study
It is often difficult for anesthesiologists to select an ultrasound method that will give consistent results and also be a reliable way to examine the diaphragm, especially on the left side of the chest.
In this study, two anesthesiologists blinded to one another's scan results, will perform ultrasound scan of the diaphragm using three different methods and the measurements will be analyzed to see the reliability of each method.
Read the detailed description
Ultrasound assessment of the diaphragm is a portable and non-invasive option for assessing and monitoring diaphragmatic function. The diaphragm is the main muscle used for breathing. It is a muscular organ that lies in between the thorax (chest) and abdomen. By moving up and down, it helps in our breathing by aiding both the right and the left lung to inflate and deflate. Assessing diaphragmatic function provides meaningful information in the setting of chronic lung diseases, obesity and diseases of nerve and muscle dysfunction and in assessing the diaphragmatic function before and after surgery. However, ultrasound assessment of the diaphragm on the left side of chest is sometimes difficult or impossible in a large proportion of patients.
There are currently three ultrasound methods to examine the diaphragm, and to date, it is not clear which technique should be used as the most reliable method. The purpose of this research study is to find out how much reliable the different ultrasound methods are in assessing the movement of the diaphragm during respiration.
In this study, two anesthesiologists blinded to one another's scan results, will perform ultrasound scan of the diaphragm using three different methods and the measurements will be analyzed to see the reliability of each method. The investigators believe that the results of this study can guide medical professionals in selecting an ultrasound method that will give consistent results and a more reliable way to examine the diaphragm, especially on the left side of the chest.
- Conditions
- Diaphragm Issues
- Keywords
- Diaphragm ultrasound, Intra-rater analysis, Inter-rater analysis, Zone of Apposition, ZOA, Diaphragmatic diseases, Dome of diaphragm, DOD, Thickening Fraction, TF
What is being measured
The primary outcome is the main question the study is designed to answer.
To measure the intra-rater reliability of the excursion of the zone of apposition, (ZOA)
To measure the intra-rater (between two measurements of the same scanner) reliability of the excursion of the ZOA using a linear probe over the lateral chest wall, quantified by Intraclass correlation coefficients (ICC).
Measured: Through study completion, an average of 2 years
To measure the inter-rater reliability of the excursion of the zone of apposition, (ZOA)
To measure the inter-rater (between two ultrasound scanners) reliability of the excursion of the zone of apposition, (ZOA) using a linear probe over the lateral chest wall, quantified by Intraclass correlation coefficients (ICC).
Measured: Through study completion, an average of 2 years
Secondary outcomes (7)
To measure the intra-rater reliability of the excursion of the dome of the diaphragm (DOD)
To measure the intra-rater (between two measurements of the same scanner) reliability of the excursion of the DOD measured using a curvilinear probe via the subcostal abdominal window, quantified by ICCs
Measured: Through study completion, an average of 2 years
To measure the inter-rater reliability of the excursion of the dome of the diaphragm (DOD)
To measure the inter-rater (between two ultrasound scanners) reliability of the excursion of the DOD measured using a curvilinear probe via the subcostal abdominal window, quantified by ICCs
Measured: Through study completion, an average of 2 years
To measure intra-rater reliability of the Thickening Fraction, (TF) of the ZOA
To measure intra-rater (between two measurements of the same scanner) reliability of the Thickening Fraction, TF of the ZOA measured using a linear probe over the lateral chest wall, quantified by ICCs.
Measured: Through study completion, an average of 2 years
To measure inter-rater reliability of the Thickening Fraction, (TF) of the ZOA
To measure inter-rater (between two ultrasound scanners) reliability of the Thickening Fraction, (TF) of the ZOA measured using a linear probe over the lateral chest wall, quantified by ICCs.
Measured: Through study completion, an average of 2 years
To measure the distribution of diaphragmatic measurements obtained for the ZOA method (Excursion of the ZOA)
To measure the distribution of diaphragmatic measurements obtained for the ZOA method (Excursion of the ZOA) using F-tests for ICCs
Measured: Through study completion, an average of 2 years
To measure the distribution of diaphragmatic measurements obtained for the DOD method
To measure the distribution of diaphragmatic measurements obtained using the DOD method (Excursion of the DOD) using F-tests for ICCs
Measured: Through study completion, an average of 2 years
To measure the distribution of diaphragmatic measurements obtained for the Thickening Fraction method (TF of the ZOA)
To measure the distribution of diaphragmatic measurements obtained for the Thickening fraction method (TF of the ZOA) using F-tests for ICCs
Measured: Through study completion, an average of 2 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Aug 2026
- Study startAug 2026 (estimated)
- Primary completionMar 2028 (estimated)
- Study completionJul 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Diaphragm IssuesStudies of the same condition, open and under way.
- More trials run by University Health Network, TorontoThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 58 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University Health Network, Toronto
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Laura Giron-Arango, MD, Principal investigator, University Health Network, Toronto
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07747532
- Sponsor's protocol ID
- 26-5084
- Acronym
- ReDU analysis
- Status last verified
- Jul 2026
- First submitted
- 21 Jul 2026
- Last updated
- 5 Aug 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 5 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Reliability of Diaphragm Ultrasound: Intra- and Interrater Analysis
- ClinicalTrials.gov ID
- NCT07747532
- Acronym / sponsor ID
- ReDU analysis / 26-5084
- Conditions
- Diaphragm Issues
- Keywords
- Diaphragm ultrasound, Intra-rater analysis, Inter-rater analysis, Zone of Apposition, ZOA, Diaphragmatic diseases, Dome of diaphragm, DOD, Thickening Fraction, TF
- Study type
- Observational
- Recruitment status
- Not yet recruiting
- Enrolment
- 58 participants (estimated)
- Lead sponsor
- University Health Network, TorontoUniversity, hospital or other
- Study start
- Aug 2026 (estimated)
- Primary completion
- Mar 2028 (estimated)
- Study completion
- Jul 2028 (estimated)
- First posted
- 5 Aug 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
It is often difficult for anesthesiologists to select an ultrasound method that will give consistent results and also be a reliable way to examine the diaphragm, especially on the left side of the chest.
In this study, two anesthesiologists blinded to one another's scan results, will perform ultrasound scan of the diaphragm using three different methods and the measurements will be analyzed to see the reliability of each method.
Detailed description
Ultrasound assessment of the diaphragm is a portable and non-invasive option for assessing and monitoring diaphragmatic function. The diaphragm is the main muscle used for breathing. It is a muscular organ that lies in between the thorax (chest) and abdomen. By moving up and down, it helps in our breathing by aiding both the right and the left lung to inflate and deflate. Assessing diaphragmatic function provides meaningful information in the setting of chronic lung diseases, obesity and diseases of nerve and muscle dysfunction and in assessing the diaphragmatic function before and after surgery. However, ultrasound assessment of the diaphragm on the left side of chest is sometimes difficult or impossible in a large proportion of patients.
There are currently three ultrasound methods to examine the diaphragm, and to date, it is not clear which technique should be used as the most reliable method. The purpose of this research study is to find out how much reliable the different ultrasound methods are in assessing the movement of the diaphragm during respiration.
In this study, two anesthesiologists blinded to one another's scan results, will perform ultrasound scan of the diaphragm using three different methods and the measurements will be analyzed to see the reliability of each method. The investigators believe that the results of this study can guide medical professionals in selecting an ultrasound method that will give consistent results and a more reliable way to examine the diaphragm, especially on the left side of the chest.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Patient aged 18 years or over who are scheduled for any elective surgical procedure at Toronto Western Hospital or Women's College Hospital, Toronto.
Key inclusion criteria (4 listed)
- Any elective surgical patient
- Age ≥18 years
- American Society of Anesthesiologists class I to III
Key exclusion criteria (6 listed)
- Participants will not be eligible for the study if any of the exclusion criteria is present:
- Pregnancy - patients will be asked if they are pregnant or not and screened post-consent from their medical chart.
- History of diaphragmatic dysfunction
- Previous surgical procedures on the lung, thorax or diaphragm.
- Inability to understand the study activities and provide informed consent when explained about the study and the consent process
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
To measure the intra-rater reliability of the excursion of the zone of apposition, (ZOA)
Time frame: Through study completion, an average of 2 years
To measure the intra-rater (between two measurements of the same scanner) reliability of the excursion of the ZOA using a linear probe over the lateral chest wall, quantified by Intraclass correlation coefficients (ICC).
To measure the inter-rater reliability of the excursion of the zone of apposition, (ZOA)
Time frame: Through study completion, an average of 2 years
To measure the inter-rater (between two ultrasound scanners) reliability of the excursion of the zone of apposition, (ZOA) using a linear probe over the lateral chest wall, quantified by Intraclass correlation coefficients (ICC).
7 secondary outcomes
To measure the intra-rater reliability of the excursion of the dome of the diaphragm (DOD)
Time frame: Through study completion, an average of 2 years
To measure the inter-rater reliability of the excursion of the dome of the diaphragm (DOD)
Time frame: Through study completion, an average of 2 years
To measure intra-rater reliability of the Thickening Fraction, (TF) of the ZOA
Time frame: Through study completion, an average of 2 years
To measure inter-rater reliability of the Thickening Fraction, (TF) of the ZOA
Time frame: Through study completion, an average of 2 years
To measure the distribution of diaphragmatic measurements obtained for the ZOA method (Excursion of the ZOA)
Time frame: Through study completion, an average of 2 years
To measure the distribution of diaphragmatic measurements obtained for the DOD method
Time frame: Through study completion, an average of 2 years
To measure the distribution of diaphragmatic measurements obtained for the Thickening Fraction method (TF of the ZOA)
Time frame: Through study completion, an average of 2 years
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 5 Aug 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Laura Giron-Arango, MD principal investigator
University Health Network, Toronto
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Diaphragm Issues, run by University Health Network, Toronto at 1 site in Canada.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 5 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Canada. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Jayanta Chowdhury (4166035800 ext. 2016, jayanta.chowdhury@uhn.ca), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
To measure the intra-rater reliability of the excursion of the zone of apposition, (ZOA) (time frame: Through study completion, an average of 2 years). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 5 Aug 2026; AzTrials last refreshed its copy on 7 Nov 2026.