[Unilateral pulmonary fibrosis following ipsilateral single-lung ventilation and anesthesia]

We experienced a rare case of unilateral pulmonary fibrosis following ipsilateral single-lung ventilation and anesthesia. A 75-year-old man with a 1-pack a day smoking history for 50 years was scheduled for right upper and middle lobectomy for lung cancer. The trachea and left bronchus were intubated with a 37-Fr double-lumen endobronchial tube, and anesthesia was maintained with oxygen, nitrous oxide, isoflurane, and epidural lidocaine. Left single-lung ventilation was maintained for 3.5 hours with FIO2 at 0.8-1.0, vital capacity at 10 ml.kg-1, and peak inspiratory pressure at 25 cmH2O. On postoperative day 55, reticular nodular density in chest roentogenography appeared only in the left lung while right lung showed pleural fluid and pneumonia. On postoperative day 105, a high-resolution computed tomographic scan revealed honeycomb pattern in the left lung and organized pneumonia in the right lung. The patient died from respiratory failure on postoperative day 155, and autopsy was not performed. Although the causative mechanisms of unilateral pulmonary fibrosis in this case was unclear, the patient had not been exposed to any drugs and inhalation agents known to induce pulmonary fibrosis. We speculate that high oxygen concentration, high peak inspiratory pressure, and overdistension of the left lung during the left single-lung ventilation and anesthesia were likely major initiating and contributing factors.