Chest Radiological Findings of Patients With Severe H1N1 Pneumonia Requiring Intensive Care
Open Access
- 12 June 2014
- journal article
- research article
- Published by SAGE Publications in Journal of Intensive Care Medicine
- Vol. 31 (1), 51-60
- https://doi.org/10.1177/0885066614538753
Abstract
Introduction: A new strain of human influenza A (H1N1) virus originated from Mexico in 2009 and spread to more than 190 countries and territories. The World Health Organization (WHO) declared it a level 6 (highest level) pandemic. In August 2010, WHO announced that the H1N1 2009 influenza virus had moved into the postpandemic period. The WHO also declared that this flu strain is expected to continue to circulate as a seasonal virus “for some years to come.” The objective of this study is to describe the chest radiographic and computed tomography (CT) findings of patients with severe H1N1 pneumonia admitted to the intensive care unit (ICU) during the 2009 pandemic. Hypothesis: Patients with severe H1N1 pneumonia requiring ICU admission have extensive radiographic and CT abnormalities. Methods: Eighteen patients, aged 23 to 62 (mean 41), admitted to the ICU at UCLA-Olive View Medical Center with a primary diagnosis of pandemic H1N1 infection, confirmed either via rapid influenza detection test or by real-time reverse transcriptase polymerase chain reaction assay, formed the study population. All patients had chest x-ray (CXR) within 24 hours of admission and 5 patients had CT examinations. In this retrospective study, images were evaluated for the pattern (ground-glass opacities, consolidation, reticular opacities, and nodular opacities), distribution (unilateral/bilateral, upper/middle/lower lung zone, and central/peripheral/peribronchovascular), and extent (focal/multifocal/diffuse; number of lung zones) of abnormalities. Results: All (100%) patients had abnormal CXR and CT studies. The predominant radiographic findings were ground-glass opacities (16 of 18; 89%), consolidation (16 of 18; 89%), and reticular opacities (6 of 18, 33%). The radiographic abnormalities were bilateral in 17 (94%) patients; involved lower lung distribution in 18 (100%) patients, and mid and lower lung distribution in 16 (89%) patients. Radiographic abnormalities were peribronchovascular in 11 (61%) patients and multifocal in 10 (56%). Sixteen (89%) patients had extensive abnormalities involving 3 or more lung zones. The patients requiring mechanical ventilation had a higher incidence of bilateral, diffuse consolidation in a peribronchovascular distribution on chest radiographs. The predominant CT abnormalities were consolidation (5 of 5; 100%), ground-glass opacities (5 of 5; 100%), and nodular opacities (3 of 5, 60%). The CT findings were peribronchovascular and multifocal in 4 (80%) patients and extensive and bilateral in all (100%) patients. Conclusions: Patients with H1N1 pneumonia admitted to the ICU had bilateral, extensive CXR, and CT abnormalities. Consolidations and ground-glass opacities were the most common imaging findings, predominantly affecting mid and lower lung zones. Imaging abnormalities were peribronchovascular and multifocal in a majority of patients.Keywords
This publication has 17 references indexed in Scilit:
- Intensive care unit patients with 2009 pandemic influenza A (H1N1pdm09) virus infection – United States, 2009Influenza and Other Respiratory Viruses, 2012
- Computed tomography findings from patients with ARDS due to Influenza A (H1N1) virus-associated pneumoniaEuropean Journal of Radiology, 2012
- H1N1 pneumonia: our experience in 50 patients with a severe clinical course of novel swine-origin influenza A (H1N1) virus (S-OIV)La radiologia medica, 2011
- Image Findings of Patients with H1N1 Virus Pneumonia and Acute Respiratory FailureAcademic Radiology, 2010
- High-resolution computed tomography findings from adult patients with Influenza A (H1N1) virus-associated pneumoniaEuropean Journal of Radiology, 2010
- Pandemic (H1N1) 2009 influenzaBritish Journal of Anaesthesia, 2010
- Critical Care Services and 2009 H1N1 Influenza in Australia and New ZealandNew England Journal of Medicine, 2009
- Hospitalized Patients with 2009 H1N1 Influenza in the United States, April–June 2009New England Journal of Medicine, 2009
- Fleischner Society: Glossary of Terms for Thoracic ImagingRadiology, 2008
- Viral Pneumonias in Adults: Radiologic and Pathologic FindingsRadioGraphics, 2002