Pulmonary nocardiosis presenting as exacerbation of chronic pulmonary disease

Abstract

Background: Pulmonary nocardiosis (PN) occurs in chronic pulmonary disease (CPD) in the absence of traditional risk factors. Clinical features that differentiate bacterial exacerbations (AE-CPDb) from PN-related exacerbations (AE-CPDPN) are not well described. Objectives: To describe a series of AE-CPDPN without traditional risk factors and compare clinical features, radiology and outcomes with age, gender and CLD-type matched AE-CPDb. Materials and methods: Single-center retrospective review and case-control study. Results: AE-CPDPN had longer duration of symptoms and more leukocytosis at hospitalization. AE-CPDb 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-CPDb were discharged on domiciliary oxygen (OR 5.27, p = 0.01). On logistic regression, AE-CPDPN 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-CPDPN died. Respiratory failure requiring oxygen, NIPPV or mechanical ventilation was associated with mortality in AE-CPDPN. Conclusion: PN is a rare cause of AE-CPD and can be suspected by longer symptom duration, more leukocytosis, consolidation and cavitation. AE-CPDPN is associated with longer hospital stay and mechanical ventilation. Respiratory failure is associated with mortality in AE-CPDPN. 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 (CPDPN) 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-CPDPN.