Abstract
Background. Bronchoscopy using a high-flow nasal cannula (HFNC) in patients with acute respiratory failure (ARF) and underlying lung cancer has not yet been reported. Case. A 34-year-old woman visited our hospital due to worsening cough with sputum. Chest X-ray revealed an abnormal shadow in the lung fields. On the day following admission, she developed ARF. An HFNC was used during diagnostic bronchoscopy to maintain oxygenation, and diagnostic bronchoalveolar lavage (BAL: 50 ml×2 times) was successfully completed. A cytological evaluation of the BAL fluid revealed adenocarcinoma; thus, the patient was diagnosed with pulmonary lymphangitic carcinomatosis. We explained the risks, particularly lung injury, and benefits of tyrosine kinase inhibitor (TKI) treatment to the patient and then started oral epidermal growth factor receptor (EGFR)-TKI therapy with erlotinib with her written consent. We selected erlotinib because it has been indicated as being effective in EGFR mutation-negative lung cancer. Her respiratory symptoms rapidly improved. The final results of molecular testing of EGFR revealed that the cancer harbored the EGFR exon 19 deletion. Conclusions. HFNC may be an effective tool for maintaining oxygenation during diagnostic bronchoscopy in patients with ARF. For the appropriate molecular diagnosis of lung cancer in patients with ARF, the samples should be subjected to a molecular analysis.
