to evaluate the difference between the tracheal intubation (TI) and rigid bronchoscopy (RB) under general anesthesia on patients with transbronchial cryobiopsy.

To evaluate the difference between the tracheal intubation (TI) and rigid bronchoscopy (RB) under general anesthesia on patients with transbronchial cryobiopsy. Comparing the difference between two groups in the operating duration, extubation duration, total anesthesia time, heart rate, blood pressure and arterial blood gas analysis. This is a prospective, randomized, controlled trial.

Inclusion Criteria:

1. The patients are admitted in the institution as ILD, while undefined after thorough history collection, laboratory examination and radiological data.
2. Transbronchial cryobiopsy(TBCB) is indicated by clinicians for definitive diagnosis and patients are content with the examination with agreement signed.
3. Blood gas analysis, routine blood test, ECG examination, coagulation function, immunological examination, chest HRCT, and liver/kidney function test have been completed

Exclusion Criteria:

1. The radiological data indicates non-ILD
2. The clinical examinations mentioned above are not completed.
3. The patient cannot endure or does not agree the procedure.