Necrotizing pneumonia in adults: multidisciplinary management

Regeneration of Pulmonary Tissue in a Calf Model of Fibrinonecrotic Bronchopneumonia Induced by Experimental Infection with Chlamydia Psittaci

Pneumonia is a cause of high morbidity and mortality in humans. Animal models are indispensable to investigate the complex cellular interactions during lung injury and repair in vivo. The time sequence of lesion development and regeneration is described after endobronchial inoculation of calves with Chlamydia psittaci. Calves were necropsied 2-37 days after inoculation (dpi). Lesions and presence of Chlamydia psittaci were investigated using histology and immunohistochemistry. Calves developed bronchopneumonia at the sites of inoculation. Initially, Chlamydia psittaci replicated in type 1 alveolar epithelial cells followed by an influx of neutrophils, vascular leakage, fibrinous exudation, thrombosis and lobular pulmonary necrosis. Lesions were most extensive at 4 dpi. Beginning at 7 dpi, the number of chlamydial inclusions declined and proliferation of cuboidal alveolar epithelial cells and sprouting of capillaries were seen at the periphery of necrotic tissue. At 14 dpi, most of the necrosis had been replaced with alveoli lined with cuboidal epithelial cells resembling type 2 alveolar epithelial cells and mild fibrosis, and hyperplasia of organized lymphoid tissue were observed. At 37 dpi, regeneration of pulmonary tissue was nearly complete and only small foci of remodeling remained. The well-defined time course of development and regeneration of necrotizing pneumonia allows correlation of morphological findings with clinical data or treatment regimen.

Necrotising pneumonia caused by non-PVL Staphylococcus aureus with 2-year follow-up

Necrotising pneumonia (NP) is a rare but life-threatening complication of pulmonary infection. It is characterised by progressive necrosis of lung parenchyma with cavitating foci evident upon radiological investigation. This article reports the case of a 52-year-old woman, immunocompetent healthcare professional presenting to Accident and Emergency with NP and Staphylococcus aureus septicaemia. The cavitating lesion was not identified on initial chest X-ray leading to a delay in antimicrobial optimisation. However, the patient went on to achieve a full symptomatic recovery in 1 month and complete radiological recovery at 2-year follow-up. Long-term prognosis for adult cases of NP currently remains undocumented. This case serves as the first piece of published evidence documenting full physiological and radiological recovery following appropriate treatment of NP in an immunocompetent adult patient.

Management of necrotizing pneumonia and pulmonary gangrene: a case series and review of the literature

BACKGROUND

Necrotizing pneumonia is an uncommon but severe complication of bacterial pneumonia, associated with high morbidity and mortality. The availability of current data regarding the management of necrotizing pneumonia is limited to case reports and small retrospective observational cohort studies. Consequently, appropriate management for these patients remains unclear.

OBJECTIVE

To describe five cases and review the available literature to help guide management of necrotizing pneumonia.

METHODS

Cases involving five adults with respiratory failure due to necrotizing pneumonia admitted to a tertiary care centre and infected with Streptococcus pneumoniae (n=3), Klebsiella pneumoniae (n=1) and methicillin-resistant Staphylococcus aureus (n=1) were reviewed. All available literature was reviewed and encompassed case reports and retrospective reviews dating from 1975 to the present.

RESULTS

All five patients received aggressive medical management and consultation by thoracic surgery. Three patients underwent surgical procedures to debride necrotic lung parenchyma. Two of the five patients died in hospital.

CONCLUSIONS

Necrotizing pneumonia often leads to pulmonary gangrene. Computed tomography of the thorax with contrast is recommended to evaluate the pulmonary vascular supply. Further study is necessary to determine whether surgical intervention, in the absence of pulmonary gangrene, results in better outcomes.

[Multidisciplinary approach of ventilated necrotizing pneumonia]

Les pneumopathies infectieuses peuvent se compliquer, du fait de facteurs liés aux germes, à l’hôte ou à l’interaction entre les deux, par la survenue d’une nécrose et/ou d’une destruction du parenchyme pulmonaire. La nécrose et la destruction du parenchyme pulmonaire sont à l’origine de deux entités cliniques principales, les abcès pulmonaires et les pneumonies nécrosantes (PN). Les PN sont des entités rares mais dont le pronostic est redoutable. Elles sont caractérisées par une hépatisation diffuse, possiblement bilatérale du parenchyme pulmonaire avec cavitations et nécrose. Les PN sont généralement associées à un sepsis sévère et à une insuffisance respiratoire aiguë. Nous envisagerons la physiopathologie et le traitement médical qui comprend des mesures symptomatiques, le support des différentes défaillances d’organe, en particulier respiratoires, et le traitement antibiotique. Les indications chirurgicales et leurs modalités seront aussi détaillées. Une prise en charge multidisciplinaire associant réanimateurs, pneumologues, infectiologues, radiologues, chirurgiens et kinésithérapeutes doit permettre d’améliorer les taux de survie et surtout la qualité de vie des patients à distance d’une PN.