Safety of transbronchial lung criobiopsy in mechanically ventilated patients in critical care. Multicenter study

Background: Diagnosis of diffuse lung infiltrates (DLI) in acute mechanically ventilated (MV) patients is challenging. Lung biopsies are useful when conventional methods fail, but the best method is not established. Transbronchial lung cryobiopsy (TBLCB) gets bigger samples and increases diagnostic yield of conventional method, but it has not been tested in MV patients.

Aims: To analyze feasibility, safety and potential role of TBLCB in the diagnosis of DLI in MV patients.

Methods: Multicenter, prospective study. We included MV patients with non-diagnosed DLI with conventional methods. Oro-tracheal tube (OTT) was changed to a Bronchoflex Rüsh® to allow the use of a haemostatic balloon, which was allocated in the bronchi previous to obtaining TBLCB (2.4mm cryoprobe) through a flexible bronchoscope.

Results: In 17 patients (median age 65 (51-76); PaFi 162.3 (118.9–264.9)) a median of 3 TBLCB/patient were performed (valid sample in 100%). Change of the OTT was related to transitory complications (hypoxemia, hypotension). During TBLCB, 1 patient had a massive bleeding requiring selective intubation <24h

Histological results led to changes in therapeutic management in 15 patients. 10 patients died, but none were related to the TBLCB.
Conclusions: TBLCB is a feasible technique to obtain lung biopsies in MV patients. Pathological results had a direct clinical impact in the management of undiagnosed pulmonary infiltrates in MV patients. Further research is needed to establish risk-benefit and diagnostic yield in these patients.