An interventional study of Diaphragmatic ultrasound in Weaning Mechanical Ventilation, ICU Ill Patients and Diaphragm Dysfunction, sponsored by Hospital de Clinicas de Porto Alegre. Recruiting at 1 site in Brazil. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-08-07.
Sponsored by Hospital de Clinicas de Porto Alegre · Not applicable, Interventional, and Diagnostic
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.
1,780 studies on the registry are indexed under Critical Illness; 442 are open to participants now.
This study's planned enrollment of 220 is above the median of 90 across 926 interventional studies indexed under Critical Illness.
Browse Critical Illness studies →Hospital de Clinicas de Porto Alegre is the lead sponsor of 456 studies on the registry; 61 are open to participants now.
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Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
Diagnostic Test: Diaphragmatic ultrasound
In this group, patients will be assessed; however, the results of the assessment will not be shared with the attending teams.
Diagnostic Test: Diaphragmatic ultrasound
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.
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.
Time frame: At day 28
Plan to share: No
No publications or documents are linked to this record.
Start is estimated for Aug 2026; primary completion for Apr 2028, 20 months later.
Of 399 non-industry interventional studies with no phase under Critical Illness, half reached primary completion within 21 months of starting (the median), counting those still running; a quarter within 12 and three quarters within 40. This study's planned 20 months is close to that.
Counting every sponsor, half of 403 studies reached it within 21 months; a quarter within 12 and three quarters within 40.
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