Elsevier

Journal of Critical Care

Volume 18, Issue 3, September 2003, Pages 173-180
Journal of Critical Care

Pandemic influenza-implications for critical care resources in australia and new zealand

https://doi.org/10.1016/j.jcrc.2003.08.008Get rights and content

Abstract

Objectives: To quantify resource requirements (additional beds and ventilator capacity), for critical care services in the event of pandemic influenza.

Materials and Methods: Cross-sectional survey about existing and potential critical care resources. Participants comprised 156 of the 176 Australasian (Australia and New Zealand) critical care units on the database of the Australian and New Zealand Intensive Care Society (ANZICS) Research Centre for Critical Care Resources. The Meltzer, Cox and Fukuda model was adapted to map a range of influenza attack rate estimates for hospitalisation and episodes likely to require intensive care and to predict critical care admission rates and bed day requirements. Estimations of ventilation rates were based on those for community-acquired pneumonia.

Results: The estimated extra number of persons requiring hospitalisation ranged from 8,455 (10% attack rate) to 150,087 (45% attack rate). The estimated number of additional admissions to critical care units ranged from 423 (5% admission rate, 10% attack rate) to 37,522 (25% admission rate, 45% attack rate). The potential number of required intensive care bed days ranged from 846 bed days (2 day length of stay, 10% attack rate) to 375,220 bed days (10 day length of stay, 45% attack rate). The number of persons likely to require mechanical ventilation ranged from 106 (25% of projected critical care admissions, 10% attack rate) to 28,142 (75% of projected critical care admissions, 45% attack rate). An additional 1,195 emergency ventilator beds were identified in public sector and 248 in private sector hospitals. Cancellation of elective surgery could release a potential 76,402 intensive care bed days (per annum), but in the event of pandemic influenza, 31,150 bed days could be required over an 8- to 12-week period.

Conclusion: Australasian critical care services would be overwhelmed in the event of pandemic influenza. More work is required in relation to modelling, contingency plans, and resource allocation.

Section snippets

Methods

A postal survey was conducted in May 1999 of 180 Australasian Level I, II, and III, adult and pediatric, public and private sector, and critical care units listed on the database of the ANZICS Research Centre for Critical Care Resources. (A copy of the survey form can be found in the appendices of the published report at www.anzics.com.au/admc/registry_publications.htm).3

The study was conducted simultaneously with the annual resource survey (1998 calendar year data) with the latter dataset an

Supply of beds and mechanical ventilation

There was an overall survey response rate of 87.5% (public sector 91%, private sector 76%). Public sector critical care beds included those for both Australia and New Zealand, whilst private sector critical care beds were estimated solely for Australia. Four units were classified as high dependency units and omitted from the dataset as these sites did not have ventilatory capacity or capability.

There were 164 critical care complexes identified in both public and private sectors, 72 of these

Study limitations

This study had several limitations. The resource capabilities were determined for critical care units only, with increased ventilatory capacity generated from emergency, anesthesia, and operating room services. Not addressed were: the impact of vaccination and antivirals on demand for intensive care bed days and mechanical ventilation; quality of care issues; rapid recruitment of additional health care personnel; use of defense service medical capability and logistic support; provision of

Discussion

There are sophisticated surveillance mechanisms in place to monitor the types and spread of influenza. Pandemic influenza has not occurred in Australasia in over 30 years, however, there is little room for complacency. Recent events in North America such as the September 11 attack in 2001 focus our attention on the need for vigilance and preparedness for untoward incidents that may have a significant impact on critical care resources. The focus of the model described in the study is on planning

Classification of influenza

To estimate resource requirements for influenza pandemic, it is necessary to look at the number of admissions and bed days currently utilised by patients with influenza and pneumonia. Unfortunately, existing data sources do not distinguish influenza-specific pneumonia from other causes of community-acquired pneumonia because of previous paucity of diagnostic tests and joint classification by principal diagnostic groupings in ICD-10-AM (International Classification of Diseases, Version 10 -

Conclusion

Additional emergency ventilator bed capacity could be generated from a variety of sources and current critical care activity and bed usage decreased through a reduction in elective procedures. Currently available ICD10-AM public health data for influenza and pneumonia is an inadequate descriptor of respiratory disease activity. The number of patients requiring intensive care for influenza and pneumonia or its resultant complications can not be tracked at present. Meltzer et al5 provided a

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    This work was supported by Quality and Care Continuity Branch, Department of Human Services, Melbourne, Australia; State and Territory Departments of Health (Australian Health Ministers’ Advisory Council), Ministry of Health (New Zealand); and National Influenza Pandemic Planning Committee, Australia.

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