Elsevier

Academic Radiology

Volume 17, Issue 6, June 2010, Pages 681-685
Academic Radiology

Rapid Communication
Image Findings of Patients with H1N1 Virus Pneumonia and Acute Respiratory Failure

https://doi.org/10.1016/j.acra.2010.03.013Get rights and content

Rationale and Objectives

The aim of this study was to assess the findings of chest radiography and high-resolution computed tomography in patients requiring intensive care unit treatment for severe H1N1 virus pneumonia.

Materials and Methods

In 2009, 10 patients required treatment in an intensive care unit for confirmed H1N1 pneumonia. All patients underwent chest radiography and high-resolution computed tomography. All 10 patients required mechanical ventilation because of respiratory failure. Nine patients presented with severe acute respiratory distress syndrome, and one patient died. Four patients underwent extracorporeal membrane oxygenation (ECMO) therapy. The results of chest radiography and high-resolution computed tomographic scans of these patients were systematically analyzed.

Results

The mean age of all patients was 44.1 ± 12.3 years. All 10 patients showed abnormal results on chest radiography. The radiographic abnormalities were bilateral and multifocal in 10 patients. The predominant radiographic findings were consolidations (n = 9), ground-glass opacities (n = 8), and reticular opacities (n = 2). The most frequent computed tomographic findings at presentation consisted of bilateral ground-glass opacities (n = 9), pleural effusion (n = 9), areas of consolidation (n = 8), interstitial marking (n = 8), and crazy paving (n = 4). All patients undergoing ECMO therapy showed extensive bilateral ground-glass opacities, multifocal areas of consolidation, and crazy paving. Pleural effusion was present in three of four patients undergoing ECMO therapy.

Conclusion

Patients requiring treatment in an intensive care unit for severe H1N1 pneumonia are at high risk for developing acute respiratory distress syndrome and frequently require ECMO therapy.

Section snippets

Study Population

In 2009, 10 patients at our institution required ICU treatment for laboratory-confirmed H1N1 virus pneumonia. All 10 patients had initially presented with influenza-like illness, thereby fulfilling the clinical criteria for diagnosing new influenza A infection as established by the Robert Koch Institute. Our study group of patients consisted of six men and four women with a mean age of 44.1 ± 12.3 years. Preexisting medical conditions were present in three patients, including one patient with

Results

The chest radiographic and high-resolution computed tomographic images available for review were obtained an average of 4 days after ICU admission. All 10 patients showed abnormal findings on chest radiography. The abnormalities were bilateral and multifocal in all patients. These findings consisted of consolidations (n = 9), ground-glass opacities (n = 8), reticular opacities (n = 2), and pleural effusion (n = 8). One patient also showed atelectasis in the left lower zone.

All patients

Discussion

Seasonal influenza is an acute respiratory illness that occurs particularly during the winter months. Influenza virus belongs to the orthomyxovirus family of ribonucleic acid viruses, and human disease is predominantly caused by types A and B (8). Type A virus is the most virulent and can easily mutate. Three subtypes of the virus are currently circulating among humans (H1N1, H1N2, and H3N2) (9). The novel H1N1 virus has features of North American and Eurasian swine, avian, and human influenza

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