Critical care services and 2009 H1N1 influenza in Australia and New Zealand

Steve Webb, V. Pettila, I. Seppelt, R. Bellomo, M. Bailey, D.J. Cooper, M. Cretikos, A.R. Davies, S. Finfer, P.W.J. Harrigan, G.K. Hart, B. Howe, J.R. Iredell, C. Mcarthur, I. Mitchell, S. Morrison, A.D. Nichol, D.L. Paterson, S. Peake, B. RichardsD. Stephens, Angus Turner, M. Yung

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881 Citations (Scopus)


BACKGROUNDPlanning for the treatment of infection with the 2009 pandemic influenza A (H1N1)virus through health care systems in developed countries during winter in the NorthernHemisphere is hampered by a lack of information from similar health caresystems.METHODSWe conducted an inception-cohort study in all Australian and New Zealand intensivecare units (ICUs) during the winter of 2009 in the Southern Hemisphere. We calculated,per million inhabitants, the numbers of ICU admissions, bed-days, and daysof mechanical ventilation due to infection with the 2009 H1N1 virus. We collecteddata on demographic and clinical characteristics of the patients and on treatmentsand outcomes.RESULTSFrom June 1 through August 31, 2009, a total of 722 patients with confirmed infectionwith the 2009 H1N1 virus (28.7 cases per million inhabitants; 95% confidenceinterval [CI], 26.5 to 30.8) were admitted to an ICU in Australia or New Zealand. Ofthe 722 patients, 669 (92.7%) were under 65 years of age and 66 (9.1%) were pregnantwomen; of the 601 adults for whom data were available, 172 (28.6%) had abody-mass index (the weight in kilograms divided by the square of the height inmeters) greater than 35. Patients infected with the 2009 H1N1 virus were in the ICUfor a total of 8815 bed-days (350 per million inhabitants). The median duration oftreatment in the ICU was 7.0 days (interquartile range, 2.7 to 13.4); 456 of 706 patients(64.6%) with available data underwent mechanical ventilation for a medianof 8 days (interquartile range, 4 to 16). The maximum daily occupancy of the ICUwas 7.4 beds (95% CI, 6.3 to 8.5) per million inhabitants. As of September 7, 2009,a total of 103 of the 722 patients (14.3%; 95% CI, 11.7 to 16.9) had died, and 114(15.8%) remained in the hospital.CONCLUSIONSThe 2009 H1N1 virus had a substantial effect on ICUs during the winter in Australiaand New Zealand. Our data can assist planning for the treatment of patients duringthe winter in the Northern Hemisphere.
Original languageEnglish
Pages (from-to)1925-34
JournalThe New England Journal of Medicine
Issue number20
Publication statusPublished - 2009


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