Weaning Mechanical VentilationDUS-WEANNCT07751237
Diaphragmatic Ultrasonography in Difficult Weaning
A study testing Diaphragmatic ultrasound in people with Weaning Mechanical Ventilation and ICU Ill Patients, run by Hospital de Clinicas de Porto Alegre at 1 site in Brazil.
Trial summary
Weaning from mechanical ventilation (MV) is a gradual process that includes several steps until the complete withdrawal of ventilatory support. Difficult weaning is defined as weaning completed only after the first attempt to withdraw the patient from ventilatory support, that is, a patient who failed the first… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Weaning Mechanical Ventilation, ICU Ill Patients, Diaphragm Dysfunction
- What is being tested?
- Diaphragmatic ultrasound
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 220 participants
- Where
- 1 siteBrazil
- Study dates
- Aug 2026to Sep 2029
- Phase
- Interventional
- 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
Who may be able to join
- Adults patients receiving invasive mechanical ventilation who are classified as having difficult weaning, defined as failure of the first spontaneous breathing trial.
- Richmond Agitation-Sedation Scale (RASS) score between -2 and +1.
- Clinical stability, defined as:
- No vasopressor support or only low-dose, stable vasopressor therapy.
- Absence of significant cardiac arrhythmias or ongoing myocardial ischemia.
- Adequate oxygenation (SpO₂ >90% or PaO₂ >60 mmHg).
- Respiratory rate <35 breaths/min.
Who cannot join
- Inability to obtain informed consent.
- Pre-existing neuromuscular disease.
- Pregnancy.
- Inability to perform the ultrasound examination because of chest drains, surgical wounds, or skin lesions at the assessment sites.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Brazil1 site, 1 recruiting
- Recruiting
Hospital de Clínica de Porto Alegre
Porto Alegre, Rio Grande do Sul, 90035-903
Cassiano Teixeira, Doctor, 55 51 999687062, cassiano.rush@gmail.com
About this study
Official title: The Role of Diaphragmatic Ultrasonography in Difficult Weaning From Mechanical Ventilation: A Randomized Clinical Trial
Weaning from mechanical ventilation (MV) is a gradual process that includes several steps until the complete withdrawal of ventilatory support. Difficult weaning is defined as weaning completed only after the first attempt to withdraw the patient from ventilatory support, that is, a patient who failed the first spontaneous breathing trial (SBT). The use of ultrasound (US) to assess diaphragmatic and extradiaphragmatic muscles, such as the parasternal muscles, has been employed to determine diaphragmatic dysfunction and ventilatory effort, contributing to the decision-making process regarding weaning. Among the tools used for bedside monitoring and evaluation of patients are ventilatory variables that indicate an adequate level of ventilatory assistance in spontaneous modes through ventilatory drive, such as P0.1 (occlusion pressure in the first 100 ms) and assessment of ventilatory effort-inspiratory muscle pressure (Pmus)-which have also contributed to the downscaling of ventilatory support. However, there is still no consensus in the literature regarding predicted values or the effective role of these tools as predictors of weaning during the spontaneous breathing trial (SBT). The available studies investigating the relationship between diaphragmatic US, through measurements of diaphragmatic excursion and thickening fraction, and weaning failure from mechanical ventilation are mostly observational, which limits the strength of the current evidence. Therefore, it is essential to conduct randomized clinical trials, which are still unprecedented on this topic, to more robustly assess the efficacy of this technique as a decision-support tool during the weaning process, thereby contributing to more precise clinical practice. OBJECTIVES: The primary objective of this study is to evaluate the effect of diaphragmatic US use on ventilator-free days in patients with difficult weaning. The secondary objective is to analyze the relationship between the ventilatory variables P0.1 and Pmus, diaphragmatic US, and parasternal muscle recruitment during the SBT. METHODS: This is a randomized clinical trial, following CONSORT recommendations, which will be prospectively registered on the ClinicalTrials platform. Patients will be included after failing the first SBT. Subsequently, they will be randomized into two groups: In the shared US group, the results of diaphragmatic assessment via US will be shared with the attending team for decision-making regarding extubation. In the second group, the non-shared US group, the attending team will not have access to the diaphragmatic assessment for decision-making. EXPECTED RESULTS: It is expected that the shared US group of patients will have a shorter duration of MV and a lower number of extubation failures.
- Being tested
- Diaphragmatic ultrasound
- Keywords
- ultrasound Diaphragm, complicated weaning, Critical Illness
- Medical subject headings
- Critical Illness
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Diaphragmatic ultrasoundDiagnostic test
Diaphragmatic excursion (DE) will be assessed using a low-frequency convex transducer (2-6 MHz) positioned in the anterior subcostal region between the midclavicular and anterior axillary lines. In B-mode, a transverse scan will be performed through the liver, allowing visualization of the right hemidiaphragm as a thick, curved, hyperechoic line. The ultrasound system will then be switched to M-mode to measure maximal diaphragmatic excursion. The mean DE will be calculated from three consecutive respiratory cycles.
The diaphragmatic thickening fraction (DTF) requires measurement of diaphragm thickness at end-inspiration (Tdi) and end-expiration (Tde). Measurements will be obtained in B-mode by tracing the distance between the inner pleural and peritoneal echogenic lines. A high-frequency linear transducer (7-13 MHz) will be positioned at the zone of apposition (ZOA), between the 8th and 9th intercostal spaces, along the anterior to midaxillary line.
| Study group | Role | What they receive |
|---|---|---|
| Shared US group | Experimental | In the shared US group, when indicators of diaphragmatic dysfunction are present-Dtf < 30% and DE < 1.0 cm-the research team will notify the attending clinical team and suggest the use of preventive non-invasive ventilation (NIV) for more than 48 hours after extubation. Receives: Diagnostic Test: Diaphragmatic ultrasound |
| Non-shared US group | Other | In this group, patients will be assessed; however, the results of the assessment will not be shared with the attending teams. Receives: Diagnostic Test: Diaphragmatic ultrasound |
What is being measured
The primary outcome is the main question the study is designed to answer.
Ventilator-free days at day 28
In relation to diaphragmatic muscle function as determined by ultrasound parameters obtained during the spontaneous breathing trial (SBT) in patients with difficult weaning.
Measured: At day 28
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted7 Aug 2026
- Study startAug 2026 (estimated)
- Primary completionApr 2028 (estimated)
- Study completionSep 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Weaning Mechanical VentilationStudies of the same condition, open and under way.
- 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
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Diagnosis
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Care provider
- Enrolment
- 220 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Hospital de Clinicas de Porto Alegre
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Cassiano Teixeira, Doctor, Principal investigator, Hospital de Clínicas de Porto Alegre - RS, Brasil
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07751237
- Sponsor's protocol ID
- 20250641
- Acronym
- DUS-WEAN
- Status last verified
- Aug 2026
- First submitted
- 3 Aug 2026
- Last updated
- 7 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 7 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Role of Diaphragmatic Ultrasonography in Difficult Weaning From Mechanical Ventilation: A Randomized Clinical Trial
- ClinicalTrials.gov ID
- NCT07751237
- Acronym / sponsor ID
- DUS-WEAN / 20250641
- Keywords
- ultrasound Diaphragm, complicated weaning, Critical Illness
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 220 participants (estimated)
- Lead sponsor
- Hospital de Clinicas de Porto AlegreUniversity, hospital or other
- Study start
- Aug 2026 (estimated)
- Primary completion
- Apr 2028 (estimated)
- Study completion
- Sep 2029 (estimated)
- First posted
- 7 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.
Weaning from mechanical ventilation (MV) is a gradual process that includes several steps until the complete withdrawal of ventilatory support. Difficult weaning is defined as weaning completed only after the first attempt to withdraw the patient from ventilatory support, that is, a patient who failed the first spontaneous breathing trial (SBT). The use of ultrasound (US) to assess diaphragmatic and extradiaphragmatic muscles, such as the parasternal muscles, has been employed to determine diaphragmatic dysfunction and ventilatory effort, contributing to the decision-making process regarding weaning. Among the tools used for bedside monitoring and evaluation of patients are ventilatory variables that indicate an adequate level of ventilatory assistance in spontaneous modes through ventilatory drive, such as P0.1 (occlusion pressure in the first 100 ms) and assessment of ventilatory effort-inspiratory muscle pressure (Pmus)-which have also contributed to the downscaling of ventilatory support. However, there is still no consensus in the literature regarding predicted values or the effective role of these tools as predictors of weaning during the spontaneous breathing trial (SBT). The available studies investigating the relationship between diaphragmatic US, through measurements of diaphragmatic excursion and thickening fraction, and weaning failure from mechanical ventilation are mostly observational, which limits the strength of the current evidence. Therefore, it is essential to conduct randomized clinical trials, which are still unprecedented on this topic, to more robustly assess the efficacy of this technique as a decision-support tool during the weaning process, thereby contributing to more precise clinical practice. OBJECTIVES: The primary objective of this study is to evaluate the effect of diaphragmatic US use on ventilator-free days in patients with difficult weaning. The secondary objective is to analyze the relationship between the ventilatory variables P0.1 and Pmus, diaphragmatic US, and parasternal muscle recruitment during the SBT. METHODS: This is a randomized clinical trial, following CONSORT recommendations, which will be prospectively registered on the ClinicalTrials platform. Patients will be included after failing the first SBT. Subsequently, they will be randomized into two groups: In the shared US group, the results of diaphragmatic assessment via US will be shared with the attending team for decision-making regarding extubation. In the second group, the non-shared US group, the attending team will not have access to the diaphragmatic assessment for decision-making. EXPECTED RESULTS: It is expected that the shared US group of patients will have a shorter duration of MV and a lower number of extubation failures.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (care provider)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Shared US group | Experimental | Diagnostic Test: Diaphragmatic ultrasoundIn the shared US group, when indicators of diaphragmatic dysfunction are present-Dtf < 30% and DE < 1.0 cm-the research team will notify the attending clinical team and suggest the use of preventive non-invasive ventilation (NIV) for more than 48 hours after extubation. |
| Non-shared US group | Other | Diagnostic Test: Diaphragmatic ultrasoundIn this group, patients will be assessed; however, the results of the assessment will not be shared with the attending teams. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (7 listed)
- Adults patients receiving invasive mechanical ventilation who are classified as having difficult weaning, defined as failure of the first spontaneous breathing trial.
- Richmond Agitation-Sedation Scale (RASS) score between -2 and +1.
- Clinical stability, defined as:
- No vasopressor support or only low-dose, stable vasopressor therapy.
- Absence of significant cardiac arrhythmias or ongoing myocardial ischemia.
Key exclusion criteria (4 listed)
- Inability to obtain informed consent.
- Pre-existing neuromuscular disease.
- Pregnancy.
- Inability to perform the ultrasound examination because of chest drains, surgical wounds, or skin lesions at the assessment sites.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Diaphragmatic ultrasoundDiaphragmatic excursion (DE) will be assessed using a low-frequency convex transducer (2-6 MHz) positioned in the anterior subcostal region between the midclavicular and anterior axillary lines. In B-mode, a transverse scan will be performed through the liver, allowing visualization of the right hemidiaphragm as a thick, curved, hyperechoic line. The ultrasound system will then be switched to M-mode to measure maximal diaphragmatic excursion. The mean DE will be calculated from three consecutive respiratory cycles. The diaphragmatic thickening fraction (DTF) requires measurement of diaphragm thickness at end-inspiration (Tdi) and end-expiration (Tde). Measurements will be obtained in B-mode by tracing the distance between the inner pleural and peritoneal echogenic lines. A high-frequency linear transducer (7-13 MHz) will be positioned at the zone of apposition (ZOA), between the 8th and 9th intercostal spaces, along the anterior to midaxillary line. | Diagnostic test | Non-shared US group, Shared US group |
Primary outcome
Ventilator-free days at day 28
Time frame: At day 28
In relation to diaphragmatic muscle function as determined by ultrasound parameters obtained during the spontaneous breathing trial (SBT) in patients with difficult weaning.
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 7 Aug 2026.
- Individual participant dataSharing planned: No
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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.
Cassiano Teixeira, Doctor principal investigator
Hospital de Clínicas de Porto Alegre - RS, Brasil
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Diaphragmatic ultrasound in people with Weaning Mechanical Ventilation and ICU Ill Patients, run by Hospital de Clinicas de Porto Alegre at 1 site in Brazil.
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 7 inclusion and 4 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: looking for participants now, as of the sponsor's last update on 7 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 Brazil. 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 Cassiano Teixeira, Doctor (+55 51 999687962, cassiano.rush@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Ventilator-free days at day 28 (time frame: At day 28). 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 7 Aug 2026.