Indian Journal of Medical Microbiology Medknow Publications on behalf of Indian Association of Medical Microbiology ISSN: 0255-0857 EISSN: 1998-3646 Vol. 29, Num. 2, 2011, pp. 193-194

Indian Journal of Medical Microbiology, Vol. 29, No. 2, April-June, 2011, pp. 193-194

Correspondence

H1N1: Are our critical units prepared?

IA Hamid¹, NM Kumar²

¹ Division of Cardiothoracic Surgery, Southern Railway Headquarters Hospital, Chennai - 600 023, India
² Division of Cardiac Anesthesia, Southern Railway Headquarters Hospital, Chennai - 600 023, India

Correspondence Address: I A Hamid Division of Cardiothoracic Surgery, Southern Railway Headquarters Hospital, Chennai - 600 023 India hamid1963@live.com

Date of Submission: 23-Apr-2010
Date of Acceptance: 23-Mar-2011

Code Number: mb11047

PMID: 21654122

DOI: 10.4103/0255-0857.81779

Dear Editor,

We would like to congratulate Dr. R Kanungo for the insightful Editorial, "Management of infectious disease outbreak: Lessons learnt from the H1N1," pertaining to the H1N1 pandemic that has affected India. ^[1] The World Health Organization′s (WHO′s) initial debatable response of screening may have appeared economically unsustainable and socially disruptive, incommensurate with the mildness of the disease. This ineffectual containment policy was soon replaced by mitigation, which India quickly adopted.

The significance of the H1N1 pandemic in contrast to seasonal flu is that it appears to have a predilection for the young, obese and pregnant. Its most important and almost-fatal complication is acute respiratory distress syndrome (ARDS), which can be refractory to conventional mechanical ventilation. In October 2009, 86 children in the US had died, with Kumar reporting severe illness in a young, previously healthy population from data collected from 168 critically ill patients with 2009 influenza A in Canadian intensive care units (ICUs). ^[2] Similarly, Guillermo′s study of critically ill patients at six hospitals in Mexico revealed that H1N1 had a fatality rate of 40%, with the median age being 44 years. ^[3] India′s experience may not be dissimilar.

The rapid onset of ARDS and multiorgan failure, often in young, healthy patients - a group who are not currently a priority group for H1N1 vaccination - suggest that clinical outcomes will depend on the clinicians′ ability to apply sophisticated mechanical ventilatory support and adjunct therapies. ^[4] The ARDS appears potentially reversible if the patients are triaged, categorized and treated early. More importantly, this complication appears reversible if adequate and early therapy is instituted.

As a result, ICUs are scrambling to upgrade ventilation modalities, including rescue therapies such as high-frequency oscillatory ventilation, inhaled nitric oxide and ECMO (Extracorporeal Membrane Oxygenation) after the reported successes of the Cesar trial at Leicester and of Davies in Australia, who reported a 71% survival rate with ECMO. ^[5]

It can be difficult to ascertain the incidence of H1N1 in the population and hence predict the true proportion of affected patients who require hospitalization, ICU admission or rescue therapies. In an editorial published in the JAMA, White and Angus specifically point to this fact, saying that any death from swine flu will be regrettable, "but those that result from insufficient planning and inadequate preparation will be especially tragic." ^[5],[6]

It would be prudent that Indian ICUs are adequately prepared to deal with patients afflicted by a potentially reversible respiratory failure.

References

1.	Kanungo R. Management of infectious disease outbreak: Lessons learnt from the H1N1 outbreak. Indian J Med Microbiol 2010;28:1.  Back to cited text no. 1  [PUBMED]
2.	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;302:1872-9.  Back to cited text no. 2
3.	Domínguez-Cherit G, Lapinsky SE, Macias AE, Pinto R, Espinosa-Perez L, de la Torre A, et al. Critically ill patients with 2009 influenza A(H1N1) in Mexico. JAMA 2009;302:1536-8.  Back to cited text no. 3
4.	Douglas BW, Angus DC. Preparing for the sickest patients with 2009 influenza A (H1N1) JAMA 2009;302:1905-6.   Back to cited text no. 4
5.	Giles J. Peek of Glenfield Hospital, Leicester, U.K., and his associates in the Conventional Ventilation or ECMO for Severe Adult Respiratory Failure (CESAR) trial. Lancet 2009 in press.   Back to cited text no. 5
6.	Australia and New Zealand Extracorporeal Membrane Oxygenation (ANZ ECMO) Influenza Investigators, Davies A, Jones D, Bailey M, Beca J, Bellomo R, et al. Extracorporeal membrane oxygenation for 2009 influenza A (H1N1) acute respiratory distress syndrome. JAMA 2009;302:1888-95.  Back to cited text no. 6

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