A Case of Acute Exacerbation of IPF Following Orthopedic Surgery

Abstract

INTRODUCTION: Acute exacerbation of IPF is increasingly being recognized as a common clinical event in the IPF population. The exact etiology remains unknown. Previous reports have shown an association between lung surgery, bronchoalveolar lavage, and surgical lung biopsies as a potential trigger for exacerbations of IPF. To our knowledge, there are no known cases in the literature reporting an exacerbation of IPF following a non-thoracic surgical procedure. We report a case of acute exacerbation of IPF following orthopedic surgery. CASE PRESENTATION: 78 year old male with a history of COPD (thirty pack year smoking history) and severe osteoarthritis was admitted to the NYU Hospital for Joint Diseases to undergo evaluation for total hip arthroplasty. Pre-operative evaluation was significant for a restrictive pattern with low DLCO on pulmonary function testing, as well increased interstitial markings on chest x-ray concerning for a fibrotic process. The patient reported no pulmonary symptoms, and underwent successful total hip arthroplasty without complication. On Post op day #6, the patient developed dyspnea on exertion and at rest, requiring increasing amounts of oxygen supplementation. A Chest CT was negative for pulmonary embolism, however did show bronchiectasis and evidence of fibrosis. An echocardiogram did not show evidence of heart failure. The patient was started on broad spectrum antibiotics with Vancomycin, Zosyn and Azithromycin. He also was started on high dose IV steroids (Solumedrol 60mg IV every 6 hours) for a potential COPD exacerbation. Sputum culture was positive only for Candida glabrata, and the patient completed a course of Anidulafungin. However, the patient's respiratory status continued to deteriorate, eventually requiring noninvasive positive pressure ventilation. High dose steroids were continued, as well as therapeutic anticoagulation. A repeat CT chest showed increased groundglass opacities, worsening bronchiectasis and fibrosis diffusely in a UIP pattern. A repeat echocardiogram showed new evidence for pulmonary hypertension, however otherwise normal. A trial of diuretics was initiated without a response. The patient eventually required intubation and tracheostomy, and later passed away. An autopsy revealed evidence for diffuse alveolar damage on a background of honeycombing and bronchiectasis. DISCUSSION: The etiology and pathogenesis of IPF exacerbations remains unknown. One hypothesis involves the loss of alveolar cell integrity following injury, leading to extrusion of fibrin into the alveolar spaces and remodeling. Fibrocytes can be recruited in response to chemokines generated by infection and injury and may potentiate fibrogenesis, leading to diffuse alveolar damage. This process may be triggered by pulmonary procedures, as previously reported. However, a similar inflammatory response may occur after a non-thoracic procedure, leading to the fibrogenic process. The above patient suffered an unexplained worsening fibrotic process, as evidenced by imaging, respiratory failure, and autopsy findings. Alternative causes, such as left heart failure and pulmonary embolism, were excluded. Potential infections were treated with antibiotics. Commonly proposed diagnostic criteria for IPF exacerbation were met. This is the first case to our knowledge of a non-pulmonary procedure triggering the disease process. Cases such as this are likely more common than realized and remain underreported. Clinicians should be aware of the potential for exacerbation of IPF following non-thoracic surgical procedures. CONCLUSION(S): Acute exacerbation of IPF is increasingly being recognized as a common clinical event and may occur after non-thoracic procedures, such as orthopedic surgery.