Transbronchial Lung Cryobiopsy in Undiagnosed Acute Respiratory Failure

Study Overview
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Brief Summary
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In patients with acute hypoxemic respiratory failure whose diagnosis is not established after initial evaluation, obtaining a histopathological diagnosis may improve the patients' prognosis. In our previous retrospective-controlled study, transbronchial lung cryobiopsy (TBLC) can lead to an increased chance of establishing a diagnosis compared with transbronchial lung biopsy (TBLB), with an acceptable safety profile. Therefore, further prospective randomized controlled studies exploring whether TBLC leads to improved prognosis for such patients are warranted.

Official Title
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Transbronchial Lung Biopsy Versus Transbronchial Lung Cryobiopsy in Critically Ill Patients With Undiagnosed Acute Hypoxemic Respiratory Failure: a Multicenter Prospective Study

Conditions
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Acute Respiratory Failure, Acute Respiratory Distress Syndrome

Intervention / Treatment
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* Procedure: Transbronchial lung cryobiopsy
* Procedure: Transbronchial lung biopsy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Diagnosis of acute hypoxemic respiratory failure Routine assessments [including bronchoscopy, bronchoalveolar lavage fluid cytology and pathogenic (including pathogenic mNGS) tests, blood tests, etc.] do not clarify the etiology, or there is an unexplained disease process Imaging shows a multi-lobar segmental distribution of ground glass opacity with or without consolidations Patients' families agreed to participate in the study and signed an informed consent form Exclusion Criteria: Significant hemodynamic instability Uncorrectable coagulopathy Severe pulmonary hypertension Acute coronary syndrome Intermediate-high-risk acute pulmonary embolism Acute phase of stroke Severe emphysema Aortic dissection and massive gastrointestinal bleeding Other conditions that are not suitable for participation in the clinical trial

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Transbronchial lung cryobiopsy<br> | Procedure: Transbronchial lung cryobiopsy<br>* Lung tissue was obtained by transbronchial lung cryobiopsy for subsequent pathology and clinical diagnosis.<br>|
| Active Comparator: Transbronchial lung biopsy<br> | Procedure: Transbronchial lung biopsy<br>* Lung tissue was obtained by transbronchial lung biopsy for subsequent pathology and clinical diagnosis.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Diagnostic yield | The diagnostic yield of each procedure. | 7 days after procedure | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mortality | The 28-day and 60-day of patients in each group. | 28 and 60 days | 
| Incidence of procedure related adverse events | Procedure related death, procedure related hemodynamic and respiratory instability, airway bleeding, pneumothorax and other procedure related adverse events. | 3 days after procedure | 
| Hospital stay | Length of hospital stay including ICU and general ward of respiratory medicine. | up to 60 days | 
| Organ support | Length of organ support (days). | up to 60 days |