Diaphragmatic Ultrasonography in Difficult Weaning

NCT07751237 | Recruiting

• 1 other identifier: 20250641
• Study Type: interventional
• Target: 220
• Locations: 1 country
• Sites: 1

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.

Conditions

Weaning Mechanical Ventilation; ICU Ill Patients; Diaphragm Dysfunction

Keywords

ultrasound Diaphragm; complicated weaning; Critical Illness

Outcome Measures

Primary Outcomes (1)

• 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.

  At day 28

Study Arms (2)

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.

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.

Diagnostic Test: Diaphragmatic ultrasound

Interventions

Diaphragmatic ultrasound DIAGNOSTIC_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.

Non-shared US group; Shared US group

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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.

You may not qualify if:

• 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.

Sponsors & Collaborators

• Hospital de Clinicas de Porto Alegre: lead

Study Sites (1)

Hospital de Clínica de Porto Alegre

Porto Alegre, Rio Grande do Sul, 90035-903, Brazil

RECRUITING

MeSH Terms

Conditions

Critical Illness

Condition Hierarchy (Ancestors)

Disease Attributes; Pathologic Processes; Pathological Conditions, Signs and Symptoms

Study Officials

• Cassiano Teixeira, Doctor

  Hospital de Clínicas de Porto Alegre - RS, Brasil

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Cassiano Teixeira, Doctor

CONTACT

+55 51 999687962; cassiano.rush@gmail.com

Josehelen Do Martini, Master

CONTACT

+55 51 985442212; Jdmartini@hcpa.edu.br

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: CARE PROVIDER
• Masking Details: 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.
• Purpose: DIAGNOSTIC
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: August 3, 2026
• First Posted: August 7, 2026
• Study Start: August 1, 2026
• Primary Completion (Estimated): April 1, 2028
• Study Completion (Estimated): September 1, 2029
• Last Updated: August 7, 2026

Record last verified: 2026-08

Data Sharing

• IPD Sharing: Will not share

Locations

BR (1)