Elsevier

Resuscitation

Volume 80, Issue 2, February 2009, Pages 224-230
Resuscitation

Clinical paper
Unplanned admission to intensive care after emergency hospitalisation: Risk factors and development of a nomogram for individualising risk

https://doi.org/10.1016/j.resuscitation.2008.10.030Get rights and content

Abstract

Background and aims

Unplanned admission to an intensive care unit (ICU) is associated with high mortality, having the highest incidence among patients who are emergency admissions to the hospital. This study was designed to identify factors associated with unplanned ICU admission in emergency admissions to hospital and develop an absolute risk tool to individualise the risk of an event during a hospital stay.

Methods

Emergency department (ED) and in-patient hospital data from a large teaching hospital of consecutive admissions from 1 January 1997 to 31 December 2007 aged over 14 years was included in this study. Patient data extracted from 126 826 emergency presentations admitted as in-patients consisted of demographic and clinical variables.

Results

During an 11-year period 1582 incident unplanned ICU admissions occurred. Predictors of unplanned ICU admission included older age, being male, having a higher acuity triage category and a history of co-morbid conditions. Emergency department diagnostic groups associated with higher incidence of unplanned ICU admission included: sepsis, acute renal failure, lymphatic–hematopoietic tissue neoplasms, pneumonia, chronic-airways disease and bowel obstruction. The final model used to develop the nomogram had an ROC curve AUC of 0.7.

Conclusion

This study identified factors associated with unplanned ICU admission and developed a nomogram to individualise risk prior to a patient being transferred from the ED. This nomogram provides clinicians the opportunity prior to transfer from the ED, to either (1) review the appropriateness of the ward level of planned transfer or (2) flag patients for follow-up on the general ward to assess for deterioration.

Introduction

Patients who are transferred from the general wards to the intensive care unit (ICU) for critical care management, commonly referred to as unanticipated or unplanned ICU admission,1, 2, 3 have higher in-hospital mortality than those who are admitted directly from the emergency department (ED) or the operating rooms.2, 4, 5, 6 Unplanned ICU admission in surgical patients has been used as a measure of patient safety,7 and is used by the Australian Council of Healthcare Accreditation as a reportable quality indicator.8

Many hospitals throughout the world have early warning systems to identify patients at risk of adverse events.9 However, there is scant published research that combines identification of risk factors and development of an absolute risk-based tool to identify patients at risk of unplanned admission to ICU. Accurate, objective methods of identifying at-risk patients during the initial presentation in the ED could result in identification of patients at the highest risk for unplanned ICU admission; allowing targeted interventions, such as follow-up post-ED to monitor patients in an attempt to prevent the need for transfer to ICU.

In an attempt to address this problem this study was designed to identify risk factors associated with unplanned ICU admission in emergency admissions to hospital and develop an absolute risk-based tool to individualise the risk of an event during a hospital stay.

Section snippets

Design

A retrospective design was used to examine the characteristics of unplanned admissions to ICU in-patients admitted via ED over an 11-year period.

Setting

Data for this study was collected at a 550-bed teaching hospital in the South Western region of Sydney, Australia that has approximately 55 000 hospital admissions each year. The emergency department is a major trauma centre and has approximately 35 000 presentations each year. The hospital has a 28-bed ICU with approximately 3000 admissions annually.

Results

During the 11-year study period 1582 incident unplanned ICU admissions occurred. During this period there were 126 826 emergency hospitalisations 14 years of age or older. Patient characteristics are presented in Table 1. Unplanned ICU admissions were older, male and had higher acuity triage categories in the ED. Patients discharged by the hospital in the last 28 days prior to re-presentation to ED had a higher risk of unplanned ICU admission compared to patients who had not been admitted to the

Discussion

The identification of patients at high risk of unplanned ICU admission at the time of transfer from ED to the general ward offers an important opportunity, to either (1) review the appropriateness of the ward level of transfer or (2) flag patients for follow-up on the general ward to assess for deterioration. To address the need to identify patients at risk of unplanned ICU admission, the current study has been able to identify risk factors and developed a nomogram for assigning individualised

Conclusion

In conclusion, this study has been able to identify risk factors for unplanned ICU admission in emergency hospitalisations and develop a nomogram to individualise risk before a patient is transferred from the ED. This nomogram provides clinicians the opportunity prior to transfer from ED, to either (1) review the appropriateness of the ward level of planned transfer or (2) flag patients for follow-up on the general ward to assess for deterioration.

Conflict of interest

None of the authors has any conflict of interest to declare in relation to this study.

Acknowledgment

Jan Smith extracted the unplanned ICU data from the ANZICS database.

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    A Spanish translated version of the summary of this article appears as Appendix in the final online version at doi:10.1016/j.resuscitation.2008.10.030.

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