INTRODUCTION: Organizing pneumonia (OP) may complicate a variety of collagen vascular diseases, bone marrow or heart-lung transplants, inflammatory bowel disease, inhalation of toxic gases, vasculitis, or medications. We report a case of organizing pneumonia complicated by a spontaneous tension pneumothorax that was temporally related to a prolonged course of daptomycin.
CASE PRESENTATION: A 64-year-old man was referred to the pulmonary service for cough, fever, and dyspnea. He was a former smoker receiving a six week course of daptomycin for treatment for septic arthritis following a complicated arthroscopic surgical procedure. There was no history of lung disease. The patient was cyanotic and in respiratory distress with coarse crackles auscultated bilaterally. Laboratory analysis revealed a leukocytosis and thrombocytosis. Albumin was depressed, and the transaminases were mildly elevated. Arterial blood gas demonstrated hypoxemia and a respiratory alkalosis. Chest radiograph showed mixed interstitial and airspace opacities in the upper lobes. Chest CT scan showed multi-focal ground glass opacities and bilateral consolidation. The patient was empirically treated with intravenous antibiotics for pneumonia. Fiberoptic bronchoscopy revealed normal airways with minimal secretions. Transbronchial biopsies showed evidence of an organizing pneumonia. Daptomyocin was stopped and prednisone and azithromycin were started, with rapid resolution of fever and improvement in hypoxemia. The patient was subsequently discharged, but he returned 10 days later with acute chest pain. A tension pneumothorax was diagnosed and tube thoracostomy was performed. Due to persistent air leak, the patient underwent video-assisted thoracoscopic surgery where surgical biopsies confirmed organizing pneumonia. The patient returned to his baseline functional capacity and no longer requires oxygen supplementation. Daptomycin therapy was discontinued during his hospitalization and the radiographic abnormalities resolved.
DISCUSSIONS: Organizing pneumonia (OP) is histologically defined as granulation tissue that proliferates in the lumen of distal airways. Clinically it is associated with complaints of cough, fever, and malaise that may mimic community-acquired pneumonia. Imaging may demonstrate multi-focal airspace opacities, nodules, or mixed interstitial and airspace opacity, all of which can be migratory, Open lung biopsy remains the gold standard for diagnosis, although trans-bronchial lung biopsy may sometimes provide an adequate sample. Pneumothorax has been associated with OP, but it is not a common clinical feature. OP is treated with corticosteroids. Recently macrolides have also been recommended. Obviously any potentially offending medications should be discontinued.OP has been associated with several antimicrobial drugs, including nitrofurantoin, minocycline, amphotericin, and cephalosporins. Daptomycin is a novel lipopeptide derived from Streptomyces with a primary indication for skin and deep soft tissue infection. It is not indicated for the treatment of pneumonia due to poor lung penetration. Eosinophillic pneumonia and one other case of OP have been reported.
CONCLUSION: This is the second reported case of OP attributed to daptomycin. Extended exposure to with daptomycin may have been a contributing factor. Further experience with this new and novel antibiotic would better define the spectrum and incidence of lung toxicity.
DISCLOSURE: James Prahl, No Financial Disclosure Information; No Product/Research Disclosure Information