An observational study in Ventilator Weaning and Respiratory Insufficiency, sponsored by Inonu University. Not yet recruiting. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-27.
Sponsored by Inonu University · Observational
The purpose of this study is to find out whether diaphragm ultrasound measurements, alone or combined with the rapid shallow breathing index (RSBI), can better predict successful removal of the breathing tube in adult intensive care unit patients on mechanical ventilation. Diaphragm thickening fraction and diaphragm excursion are measured with bedside ultrasound during the spontaneous breathing trial. Patients are followed after extubation to determine whether they need to be reintubated. The study does not change patient treatment; all measurements are non-invasive.
Weaning from mechanical ventilation is a critical phase of intensive care. Premature extubation increases the risk of reintubation, whereas delayed extubation increases ventilator-associated complications. The rapid shallow breathing index (RSBI) is widely used but has limited accuracy on its own. Diaphragm ultrasound, including diaphragm thickening fraction (DTF), has emerged as a reliable method for assessing diaphragm function.
This prospective, observational, single-center study is conducted in the Reanimation Intensive Care Unit of Inonu University Turgut Ozal Medical Center, Malatya, Turkey. Adult patients who have received invasive mechanical ventilation for at least 48 hours and are scheduled for a spontaneous breathing trial (SBT) are enrolled after informed consent is obtained from a legally authorized representative.
RSBI is calculated before the SBT. Right hemidiaphragm ultrasound is performed by the same investigator in all patients, who is blinded to the RSBI value and the extubation decision. DTF is measured at the beginning and at the end of the SBT, and the change in DTF between the two measurements is calculated. Diaphragm excursion is also recorded. The primary indication for mechanical ventilation is recorded using a predefined hierarchy.
The primary outcome is extubation success, defined as the absence of reintubation or of respiratory failure not manageable with non-invasive ventilation or high-flow oxygen therapy within 48 hours after extubation. The diagnostic performance of DTF, diaphragm excursion, and RSBI, alone and in combination will be compared using receiver operating characteristic curve analysis with the combined DTF+RSBI model derived from logistic regression. The planned sample size is 80 patients.
1,369 studies on the registry are indexed under Respiratory Insufficiency; 264 are open to participants now.
This study's planned enrollment of 80 is below the median of 100 across 455 observational studies indexed under Respiratory Insufficiency.
Browse Respiratory Insufficiency studies →Inonu University is the lead sponsor of 394 studies on the registry; 95 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Adult patients receiving invasive mechanical ventilation in the Reanimation Intensive Care Unit of Inonu University Turgut Ozal Medical Center who are scheduled for a spontaneous breathing trial.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
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.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
COPD
Chronic obstructive pulmonary disease: long-term lung disease that makes it hard to breathe out, including emphysema and chronic bronchitis.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Life expectancy
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Adult patients on invasive mechanical ventilation for at least 48 hours who are scheduled for a spontaneous breathing trial and extubation, undergoing diaphragm ultrasound and RSBI measurement.
Diagnostic Test: Diaphragm Ultrasonography · Diagnostic Test: Rapid Shallow Breathing Index
Right hemidiaphragm ultrasound measuring diaphragm thickening fraction at the beginning and end of the spontaneous breathing trial, the change between the two, and diaphragm excursion. Performed by a single investigator blinded to RSBI and the extubation decision.
Ratio of respiratory frequency to tidal volume (breaths/min/L) calculated before the spontaneous breathing trial.
Diagnostic Performance of Combined DTF and RSBI for Predicting Extubation Success
Area under the receiver operating characteristic curve (AUC) of the combined diaphragm thickening fraction and RSBI model compared with RSBI alone for predicting extubation success, defined as no reintubation and no respiratory failure unmanageable with non-invasive ventilation or high-flow oxygen therapy.
Time frame: 48 hours after extubation
Diaphragm Thickening Fraction
Right hemidiaphragm thickening fraction measured by ultrasonography, calculated as (end-inspiratory thickness minus end-expiratory thickness) divided by end-expiratory thickness, expressed as a percentage.
Time frame: At the beginning and at the end of the spontaneous breathing trial
Change in Diaphragm Thickening Fraction During the Spontaneous Breathing Trial
Difference between diaphragm thickening fraction measured at the end and at the beginning of the spontaneous breathing trial, in percentage points.
Time frame: From the beginning to the end of the spontaneous breathing trial
Diaphragm Excursion
Right hemidiaphragm excursion measured by M-mode ultrasonography, in centimeters.
Time frame: At the end of the spontaneous breathing trial
Rapid Shallow Breathing Index
Ratio of respiratory frequency to tidal volume, in breaths/min/L.
Time frame: Before the spontaneous breathing trial
Hospital Mortality
Number of participants who died from any cause during the hospital stay.
Time frame: From extubation up to 28 days
ICU Length of Stay
Length of intensive care unit stay, in days.
Time frame: From ICU admission to ICU discharge, assessed up to 28 days
Hospital Length of Stay
Total length of hospital stay, in days.
Time frame: From hospital admission to hospital discharge, assessed up to 28 days
Reintubation Within 7 Days
Proportion of patients requiring reintubation within 7 days after extubation.
Time frame: 7 days after extubation
ICU Mortality
Number of participants who died from any cause during the intensive care unit stay.
Time frame: From extubation up to 28 days
No study locations are listed for this record.
Plan to share: No — Individual participant data will not be shared due to patient confidentiality and the absence of consent for data sharing beyond the study team. Aggregate results will be published in a peer-reviewed journal.
No publications or documents are linked to this record.
Start is estimated for Nov 2026; primary completion for Apr 2028, 17 months later.
Of 232 non-industry observational studies under Respiratory Insufficiency, half reached primary completion within 22 months of starting (the median), counting those still running; a quarter within 12 and three quarters within 54. This study's planned 17 months is below that.
Counting every sponsor, half of 248 studies reached it within 22 months; a quarter within 12 and three quarters within 44.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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