Chest computed tomography findings in severe influenza pneumonia occurring in neutropenic cancer patients

Abstract

OBJECTIVE:To describe the chest computed tomography findings for severe influenza H1N1 infection in a series of hospitalized neutropenic cancer patients.METHODS:We performed a retrospective systematic analysis of chest computed tomography scans for eight hospitalized patients with fever, neutropenia, and confirmed diagnoses of influenza H1N1. The clinical data had been prospectively collected.RESULTS:Six of eight patients (75%) developed respiratory failure and required intensive care. Prolonged H1N1 shedding was observed in the three mechanically ventilated patients, and overall hospital mortality in our series was 25%. The most frequent computed tomography findings were ground-glass opacity (all patients), consolidation (7/8 cases), and airspace nodules (6/8 cases) that were frequently moderate or severe. Other parenchymal findings were not common. Five patients had features of pneumonia, two had computed tomography findings compatible with bronchitis and/or bronchiolitis, and one had tomographic signs of chronicity.CONCLUSION:In this series of neutropenic patients with severe influenza H1N1 infection, chest computed tomography demonstrated mainly moderate or severe parenchymatous disease, but bronchiolitis was not a common feature. These findings associated with febrile neutropenia should elicit a diagnosis of severe viral infection.

Influenza A (H1N1) pneumonia: HRCT findings

“…( 4 , 17 , 21 ) In our sample, pleural effusion was observed in 27% of the cases, being bilateral in 52% and typically minimal. No mediastinal lymphadenopathy was identified in any of the patients studied.…”

“…This finding has not commonly been reported in the literature, and few studies have described the presence of airspace nodules in patients with H1N1 infection. ( 21 , 24 ) This can be attributed to an alternative interpretation, by some authors, of airspace nodules being focal areas of consolidation, or it can even be attributed to the fact that airspace nodules can be obscured by other findings when there is extensive involvement by the disease.…”

“…As occurred in our sample, air trapping related to H1N1 infection has rarely been described in the literature. ( 21 , 24 ) However, it should be emphasized that, in those studies, the expiratory phase, which increases sensitivity in the characterization of this pattern, was not performed. Li et al ( 21 ) found a mosaic attenuation pattern due to air trapping in 13% of their patients and related it to the use of mechanical ventilation.…”

“…( 4 , 20 , 21 , 24 ) However, in some studies, the distribution is diffuse, with no zonal predominance. ( 27 ) In our sample, the HRCT scans showed bilateral involvement in the vast majority of the cases (89%), and both lungs were similarly affected in 77% of them.…”

Distinguishing the Causes of Pulmonary Infiltrates in Patients With Acute Leukemia

“…Centrilobular nodules and bronchial wall thickening have also been reported frequently. [45][46][47][48] Blood Cultures, Serology, and Other Noninvasive Tests Patients with bacterial pneumonia might have positive blood cultures that are obtained in the context of febrile neutropenia. Among the Gram-positive organisms that cause bacteremia in neutropenic patients, viridans streptococci are the most frequently associated with pneumonia.…”