Clinical relevance of necrotizing change in patients with community-acquired pneumonia

Background and objective: Few studies have analysed a large number of patients with necrotizing pneumonia (NP) diagnosed based on computed tomography (CT) scans. The aim of the present study was to document the incidence and clinical features of NP in patients with community-acquired pneumonia (CAP). Methods: This retrospective study was conducted on CAP patients who had been admitted to a tertiary referral centre and who had available enhanced CT scan images. Patients were allocated into NP and non-NP groups, and they were compared with respect to various clinical variables. Results: Of the 830 patients included in the present study, necrotizing change was observed in 103 patients (12%). Patients with NP experienced more symptoms of pneumonia, had higher blood levels of inflammatory markers and more often required pleural drainage compared to patients with non-NP. Although the use of mechanical ventilation, vasopressor infusion, 30-day mortality, in-hospital mortality and clinical deterioration did not differ between the NP and non-NP groups, the median length of hospital stay (LOS) was significantly longer in the NP group. Multivariate analysis using Cox proportional hazards model showed that necrotizing change independently predicted LOS in patients with CAP. Conclusion: NP affects approximately one-tenth of hospitalized CAP patients. It may be associated with more severe clinical manifestations and may increase the need for pleural drainage. NP was found to be an independent predictor of LOS, but not of mortality in CAP patients.