Journal List > Tuberc Respir Dis > v.68(3) > 1001483

TOOLS
Choi, Kim, Kim, Hong, Lim, Koh, Kim, and Lim: Associated Factor Related to Major Complications of Patients with Hospitalized for 2009 H1N1 Influenza Pneumonia
Original Article
Tuberculosis and Respiratory Diseases

Tuberculosis and Respiratory Diseases 2010; 68(3): 162-167.

Published online: 31 March 2010

DOI: https://doi.org/10.4046/trd.2010.68.3.162

Associated Factor Related to Major Complications of Patients with Hospitalized for 2009 H1N1 Influenza Pneumonia

Sang-Sik Choi, M.D.1, Won Young Kim, M.D.1, Sung-Han Kim, M.D.2, Sang-Bum Hong, M.D.3, Chae-Man Lim, M.D.3, Youn-suck Koh, M.D.3, Won Kim, M.D.1, Kyung-Su Lim, M.D.1

1Department of Emergency Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.

2Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.

3Department of Respiratory and Critical Care Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.

Address for correspondence: Won Young Kim, M.D. Department of Emergency Medicine, Asan Medical Center, University of Ulsan College of Medicine, 388-1, Pungnap 2-dong, Songpa-gu, Seoul 138-736, Korea. Phone: 82-2-3010-3350, Fax: 82-2-3010-3360, wonpia@yahoo.co.kr

Received 26 January 2010       Accepted 10 March 2010

Copyright © 2010. The Korean Academy of Tuberculosis and Respiratory Diseases. All rights reserved.

Abstract

Background

To date, there are few data on the risk factors for severe cases and deaths associated with the 2009 pandemic H1N1 influenza A. Here, we describe the clinical and epidemiologic characteristics of patients hospitalized for pneumonia and identify those factors associated with the development of major complications (MC).

Methods

We reviewed the medical records of 41 cases of pneumonia admitted to a university-affiliated tertiary hospital between Aug 26 and Dec 10, 2009, and who had confirmed H1N1 influenza A based on real-time reverse transcriptase-polymerase-chain-reaction assay. There were 7,962 patients that fit these criteria. We compared the clinical features and demographic characteristics of patients who developed MC to with those who did not develop MC.

Results

During the study period, 10 patients developed MC (required admission to the intensive care unit, n=10; required ventilator therapy, n=6; death, n=4). Patients with MC were significantly older than those without MC and more frequently had underlying medical conditions (90.0% vs 41.9%, p-value <0.01). In the patients with developed MC, the median PaO2/FiO2 ratio of 230.0 (145.0~347.3) at admission and pneumonia severity index (PSI) score of 141.5 (88.3~158.5) were higher than patients without MC. However, no differences were observed in laboratory findings or in viral shedding between the 2 groups.

Conclusion

In hospitalized pneumonia patients of 2009 H1N1 influenza, old age, a history of malignancy, initial hypoxemia, PaO2/FiO2 ratio, and PSI score appear to be risk factor significantly related to developing MC. These findings might be the basis to influence strategies for admitting patients to an intensive or intermediate care unit and for pre-emptive antiviral therapy.

Keywords: Influenza A Virus, H1N1 Subtype, Pneumonia, Critical Illness, Risk Factors

Figures and Tables

Table 1
Baseline clinical characteristics of major complications (MC) group and non-MC group
trd-68-162-i001

Values are expressed as median (inter-quartile range) or n (%).

MC: major complications; DM: diabetes mellitus; BMI: body mass index; SBP: systolic blood pressure; DBP: diastolic blood pressure; PaO2: partial oxygen tension in arterial blood; FiO2: fraction of inspired oxygen; PSI: pneumonia severity index.

Table 2
Baseline laboratory findings and outcomes of the study population
trd-68-162-i002

Values are expressed as median (inter-quartile range) or n (%).

MC: major complications, WBC: White blood cell, BUN: blood urea nitrogen, CK: creatinine phosphokinase, LD: lactate dehydrogenase; BNP: B-natriuretic peptide, CRP: C-reactive protein, ABGA: arterial blood gas analysis, PaO2: partial oxygen tension in arterial blood.

References

1. Dolin R. Fauci AS, Braunwald E, Kasper DL, Hauser SL, Longo DL, editors. Chapter 180. Influenza. Harrison's principles of internal medicine. 2008. 17th ed. New York: McGraw-Hill Co., Inc.;1127–1132.
2. Centers for Disease Control and Prevention (CDC). Swine influenza A (H1N1) infection in two children: Southern California, March-April 2009. MMWR Morb Mortal Wkly Rep. 2009. 58:400–402.
3. H1N1 influenza press release [Internet]. World Health Organization. c2009. updated 2009 Dec 23; cited 2009 Dec 28. Geneva: World Health Organization;Availabe from: http://www.who.int/csr/don/2009_12_23/en/index.html.
4. H1N1 influenza A (H1N1) press release [Internet]. Korea Centers for Disease Control and Prevention. c2009. Cited 2009 Dec 28. Seoul: Korea center for Disease Control and Prevention;Available from: http://flu.cdc.go.kr.
5. Thompson WW, Shay DK, Weintraub E, Brammer L, Cox N, Anderson LJ, et al. Mortality associated with influenza and respiratory syncytial virus in the United States. JAMA. 2003. 289:179–186.
6. Vaillant L, La Ruche G, Tarantola A, Barboza P. Epidemiology of fatal cases associated with pandemic H1N1 influenza 2009. Euro Surveill. 2009. 14:pii:19309.
7. Simonsen L, Clarke MJ, Schonberger LB, Arden NH, Cox NJ, Fukuda K. Pandemic versus epidemic influenza mortality: a pattern of changing age distribution. J Infect Dis. 1998. 178:53–60.
8. New influenza A (H1N1) virus infections: global surveillance summary, may 2009. [Internet]. World Health Organization. c2009. Updated 2009 May 15; cited 2009 Dec 28. Geneva: World Health Organization;Available from: http://www.who.int/wer/2009/wer8420.pdf.
9. CDC protocol of realtime RTPCR for influenza A (H1N1) [Internet]. World Health Organization. 2009. updated 2009 Oct 6; cited 2009 Dec 28. Geneva: World Health Organization;Available from: http://www.who.int/csr/resources/publications/swineflu/realtimeptpcr/en/index.html.
10. Mandell LA, Wunderink RG, Anzueto A, Bartlett JG, Campbell GD, Dean NC, et al. Infectious Diseases Society of America/American Thoracic Society consensus guidelines on the management of community-acquired pneumonia in adults. Clin Infect Dis. 2007. 44:Suppl 2. S27–S72.
11. Fine MJ, Auble TE, Yealy DM, Hanusa BH, Weissfeld LA, Singer DE, et al. A prediction rule to identify low-risk patients with community-acquired pneumonia. N Engl J Med. 1997. 336:243–250.
12. Marras TK, Gutierrez C, Chan CK. Applying a prediction rule to identify low-risk patients with community-acquired pneumonia. Chest. 2000. 118:1339–1343.
13. Kumar A, Zarychanski R, Pinto R, Cook DJ, Marshall J, Lacroix J, et al. Critically ill patients with 2009 influenza A (H1N1) infection in Canada. JAMA. 2009. 302:1872–1879.
14. Louie JK, Acosta M, Winter K, Jean C, Gavali S, Schechter R, et al. Factors associated with death or hospitalization due to pandemic 2009 influenza A (H1N1) infection in California. JAMA. 2009. 302:1896–1902.
15. Morris AE, Stapleton RD, Rubenfeld GD, Hudson LD, Caldwell E, Steinberg KP. The association between body mass index and clinical outcomes in acute lung injury. Chest. 2007. 131:342–348.
16. Centers for Disease Control and Prevention. Intensive-care patients with severe novel influenza A (H1N1) virus infection: Michigan, June 2009. MMWR Morb Mortal Wkly Rep. 2009. 58:749–752.
17. OECD Factbook 2009: economic, environmental and social statistics [Internet]. Source OECD. c2009. cited 2009 Dec 20. Paris: Organisation for Economic Co-operation and Development;Available from: http://puck.sourceoecd.org/vl=18173601/cl=11/nw=1/rpsv/factbook 2009/11/01/04/index.htm.
18. Chien YS, Su CP, Tsai HT, Huang AS, Lien CE, Hung MN, et al. Predictors and outcomes of respiratory failure among hospitalized pneumonia patients with 2009 H1N1 influenza in Taiwan. J Infect. 2010. 60:168–174.
19. Marchiori E, Zanetti G, Hochhegger B, Rodrigues RS, Fontes CA, Nobre LF, et al. High-resolution computed tomography findings from adult patients with influenza A (H1N1) virus-associated pneumonia. Eur J Radiol. 2009. 12. 03. [Epub ahead of print].
TOOLS
Similar articles