The challenge of nonresolving pneumonia. Knowing the norms of radiographic resolution is key

Risk factors for slowly resolving pneumonia in the intensive care unit

BACKGROUND

Slowly resolving pneumonia (SRP) poses early challenges for identification and medical expense for clinicians in intensive care units (ICUs); to date, the literature has been very limited in this regard.

METHODS

This was a retrospective and cohort-based study in the ICU of a university-affiliated hospital in Shanghai. Medical records of pneumonia patients in the ICU between April 2008 and February 2011were reviewed retrospectively to evaluate the risk factors for SRP.

RESULTS

In all, 106 pneumonia patients in the ICU were identified as immune-competent with a diagnosis of bacterial pneumonia. There were 62 (58.49%) patients who showed SRP and their radiographic infiltrations were completely resolved between 5 weeks and 8 weeks. Multivariate logistic regression analysis demonstrated that initial treatment with an inappropriate antibiotic, multilobar infiltration, and a high CURB-65 score were independent risk factors for SRP, with odds ratio (OR) values of 8.338 [95% confidence interval (CI) 2.117-32.848], 11.184 (95% CI 2.526-49.514), and 2.329 (95% CI 1.172-4.626), respectively. The length of the ICU stay in the SRP group was twice as long as that of the normally resolving pneumonia (NRP) group (62.27 ± 73.73 vs. 32.25 ± 23, p = 0.002). The 28-day and 60-day mortality rates in the SRP group were 17.74% and 25.81%, respectively. In addition, the 60-day mortality rate was significantly higher in the SRP group than the NRP group (25.81% vs. 6.82%, respectively; p = 0.012). Moreover, SRP was an independent risk factor for 60-day mortality (OR 5.687, 95% CI 1.334-24.240).

CONCLUSION

Treatment with an inappropriate antibiotic, multilobar infiltration, and a high CURB-65 score were independent risk factors for SRP.

Persistent pneumonia: Underlying cause and outcome

OBJECTIVE

To identify the causes and contributing factors of persistent pneumonia in children.

METHODS

41 cases with persistent pneumonia were investigated (biochemical, microbiological, histopathological, immunological and radiological tests) to find out the underlying cause.

RESULTS

Out of 41 cases, 8 had pulmonary tuberculosis and 12 had Gram negative bacterial infections, 12 had aspiration due to gastroesophageal reflux disease or oil instillation, 3 had immunodeficiency due to HIV infection, 2 had congenital lung malformation, 2 had cardiac disorders and one had foreign body aspiration as causes of persistent pneumonia. The etiology could not be established in one case.

CONCLUSION

The most common underlying cause of persistent pneumonia were persistent infection followed by aspiration and acquired immunodeficiency.

Computed tomography for the diagnosis of infectious diseases of the chest

BACKGROUND

Pulmonary infection is a common reason for imaging of the lung in immunocompetent and immunosuppressed patients. Findings on chest radiography are nonspecific and encompass poor sensitivity. The role of computed tomography (CT) has been evolving in the diagnosis of lung infections.

OBJECTIVE

This paper reviews recent developments in the efficacy and utility of CT in the diagnosis of suspected pulmonary infections in a variety of patient populations.

METHODS

Recent published literature was reviewed to prepare this treatise on the role of CT.

CONCLUSION

Knowledge and skills at pattern recognition are crucial for the CT interpretation in lung infections. Computed tomography scan is increasingly used to increase the sensitivity of the radiologic diagnosis of thoracic infections. The greatest value of CT is when the radiograph is normal, findings are equivocal, and to differentiate infection from non-infectious disorders.

Imaging of Bacterial Pulmonary Infection in the Immunocompetent Patient

Pulmonary infection is a common reason for imaging of the lung and a common incidental finding in immunocompetent patients. Findings on chest radiography are nonspecific in defining acute infection; however, the radiologist should be aware of classically described patterns of infection, including air space, bronchopneumonia, and interstitial patterns. The radiologist must also be aware of potential limitations of the sensitivity of chest radiography. Imaging findings at computed tomography in acute infection have been poorly studied but may be more specific. Aspiration and septic emboli are additional potential radiographic patterns of infection that may be very characteristic in appearance. In the setting of nonresolving pneumonia, the differential diagnosis includes noninfectious causes as well as a variety of atypical infectious agents, specifically, mycobacterial and fungal agents, which have overlapping but distinctive clinical and radiographic presentations.

Nonresolving Pneumonia

Uncertainty over the expected clinical course of a community-acquired or nosocomial pneumonia is a common reason for pulmonary consultation. Determining which patients with prolonged pneumonia and at what point during therapy they should undergo further evaluation can be challenging. This article reviews "normal" resolution times for the most common pneumonias, risk factors for delayed resolution, and infectious and noninfectious conditions that can cause nonresolving pneumonia. An approach to the evaluation of the patient with this common problem is described.