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Diaphragmatic Ultrasonography in Difficult Weaning

The Role of Diaphragmatic Ultrasonography in Difficult Weaning From Mechanical Ventilation: A Randomized Clinical Trial

Status
Recruiting
Phases
Unknown
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07751237
Acronym
DUS-WEAN
Enrollment
220
Registered
2026-08-07
Start date
2026-08-01
Completion date
2029-09-01
Last updated
2026-08-07

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Weaning Mechanical Ventilation, ICU Ill Patients, Diaphragm Dysfunction

Keywords

ultrasound Diaphragm, complicated weaning, Critical Illness

Brief 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 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.

Interventions

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.

Sponsors

Hospital de Clinicas de Porto Alegre
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
DIAGNOSTIC
Masking
SINGLE (Caregiver)

Masking description

In the shared US group, the results of the diaphragmatic assessment and the LUS score will be disclosed to the medical and physical therapy teams of the unit. In the non-shared US group, the results of the assessment will not be disclosed.

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* 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.

Exclusion criteria

* 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.

Design outcomes

Primary

MeasureTime frameDescription
Ventilator-free days at day 28At day 28In relation to diaphragmatic muscle function as determined by ultrasound parameters obtained during the spontaneous breathing trial (SBT) in patients with difficult weaning.

Countries

Brazil

Contacts

CONTACTCassiano Teixeira, Doctor
cassiano.rush@gmail.com+55 51 999687962
CONTACTJosehelen Do Martini, Master
Jdmartini@hcpa.edu.br+55 51 985442212
PRINCIPAL_INVESTIGATORCassiano Teixeira, Doctor

Hospital de Clínicas de Porto Alegre - RS, Brasil

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Aug 8, 2026