Pulmonary Nocardiosis Presenting as Exacerbation of Chronic Pulmonary Disease

BACKGROUND: Pulmonary nocardiosis (PN) occurs in chronic pulmonary disease (CPD) in the absence of traditional risk factors. Clinical features that differentiate bacterial exacerbations (AE-CPD(b)) from PN-related exacerbations (AE-CPD(PN)) are not well described. OBJECTIVES: To describe a series of AE-CPD(PN) without traditional risk factors and compare clinical features, radiology and outcomes with age, gender and CLD-type matched AE-CPD(b). MATERIALS AND METHODS: Single-center retrospective review and case-control study. RESULTS: AE-CPD(PN) had longer duration of symptoms and more leukocytosis at hospitalization. AE-CPD(b) patients were sicker with more chronic respiratory failure (OR 33.3, p = 0.01), cardiac disease and pulmonary hypertension (OR 6.2, p = 0.008) at diagnosis. More patients with AE-CPD(b) were discharged on domiciliary oxygen (OR 5.27, p = 0.01). On logistic regression, AE-CPD(PN) was independently associated with mechanical ventilation (OR 22.3, p = 0.01), length of hospital stay (median difference, 4 days, p = 0.016) but not to hospital mortality. 22.7% of AE-CPD(PN) died. Respiratory failure requiring oxygen, NIPPV or mechanical ventilation was associated with mortality in AE-CPD(PN). CONCLUSION: PN is a rare cause of AE-CPD and can be suspected by longer symptom duration, more leukocytosis, consolidation and cavitation. AE-CPD(PN) is associated with longer hospital stay and mechanical ventilation. Respiratory failure is associated with mortality in AE-CPD(PN). KEY MESSAGES: Pulmonary nocardiosis can present in advanced chronic lung disease as an exacerbation in the absence of traditional risk factors like immunosuppression. Bronchiectasis, followed by chronic obstructive pulmonary disease are the most common chronic lung disease risk factors. Pulmonary nocardiosis is a rare cause of acute exacerbation of chronic pulmonary disease (CPD). Compared to exacerbations of CPD due to bacterial infections, nocardiosis-related exacerbations (CPD(PN)) were independently related to need for mechanical ventilation and length of hospital stay. Respiratory failure requiring oxygen, noninvasive ventilation and mechanical ventilation are associated with mortality in AE-CPD(PN). HOW TO CITE THIS ARTICLE: Kancherla R, Ramanathan RM PL, Appalaraju B, Srinivas R. Pulmonary Nocardiosis Presenting as Exacerbation of Chronic Pulmonary Disease. Indian J Crit Care Med 2019;23(10):467–474.