Postoperative respiratory failure caused by acute exacerbation of idiopathic interstitial pneumonia

We herein report a case of postoperative respiratory failure caused by acute exacerbation of undiagnosed interstitial pneumonia (IP). A 76-year-old woman underwent two subsequent operations, cholecystectomy and resection of lipoma in the neck, under general anesthesia at an interval of 12 days. Although the postoperative course of the first operation was uneventful, the patient abruptly developed respiratory failure on the 4th postoperative day (POD) of the second operation. Although steroid therapy was transiently effective to improve oxygenation, respiratory failure was gradually deteriorated. She died on the 25th POD. She had a past history of right upper lobectomy for pseudotumor resulting from cryptogenic organizing pneumonia in another hospital 4 years ago. The follow-up CT performed in this hospital demonstrated subtle foci of ground-glass opacities in the left lung; however, no diagnosis of IP had been made. Thus, we concluded that idiopathic IP had gradually advanced preoperatively, and acute exacerbation was triggered by perioperative stress. The present case warned us that acute exacerbation of IP could occur in a patient with mild symptoms. Therefore, preoperative proper diagnosis is thought to be important as acute exacerbation of IP is a highly morbid clinical event.