Non-Infectious AE-ILD and ARDS Overlap: A Fatal Combination

Introduction: There is well-documented interplay between acute-exacerbation of interstitial lung disease (AE-ILD) and acute respiratory distress syndrome (ARDS). Both syndromes present with acute respiratory failure, bilateral lung infiltrates not attributable to cardiogenic pulmonary edema, involve dysregulation of inflammatory and coagulation pathways, and show histopathologic evidence of diffuse alveolar damage.


Description: A 64-year-old female with chronic hypoxemic respiratory failure, interstitial lung disease, pulmonary fibrosis, cryptogenic organizing pneumonia, and chronic obstructive pulmonary disease presented with shortness of breath and CT chest revealing new bilateral opacities and her known fibrotic disease. She experienced progressive respiratory compromise and was intubated. She developed a pneumothorax requiring chest tube placement. Empiric broad spectrum antibiotics were started despite low suspicion for infection. She underwent bronchoscopy with transbronchial alveolar biopsy and bronchoalveolar lavage, significant for few candida albicans. Broader infectious workup was otherwise negative. She developed subcutaneous emphysema and arrested while lying flat for CT scan. CPR was initiated, with subsequent transition to comfort care measures. Post-mortem evaluation showed features of diffuse alveolar damage with patchy fibrosis and honeycombing. Thromboembolism of small and medium-sized vessels and patchy intra-alveolar hemorrhages were also noted.


Discussion: Given the overlap between AE-ILD and ARDS, it is conceivable that a large portion of AE-ILD patients with severe disease will meet Berlin criteria for ARDS, such as the patient presented here. It is important to note that AE-ILD meeting ARDS criteria portends a worse prognosis than ARDS of alternate etiologies. Some principles of treatment of ARDS are applicable in this population, including the use of lung protective ventilation and steroids. However, caution should be used when escalating PEEP in the ILD patient due to risk of barotrauma. Prone positioning has not shown benefit in AE-ILD. What remains to be seen is whether the same cellular signaling pathways are at play here, and how any differences parsed out in research to come will affect these patients’ treatment.