Original Contributions
Comparative analysis of multiple-casualty incident triage algorithms*,**

https://doi.org/10.1067/mem.2001.119053Get rights and content

Abstract

Study Objective: We sought to retrospectively measure the accuracy of multiple-casualty incident (MCI) triage algorithms and their component physiologic variables in predicting adult patients with critical injury. Methods: We performed a retrospective review of 1,144 consecutive adult patients transported by ambulance and admitted to 2 trauma centers. Association between first-recorded out-of-hospital physiologic variables and a resource-based definition of severe injury appropriate to the MCI context was determined. The association between severe injury and Triage Sieve, Simple Triage and Rapid Treatment, modified Simple Triage and Rapid Treatment, and CareFlight Triage was determined in the patient population. Results: Of the physiologic variables, the Motor Component of the Glasgow Coma Scale had the strongest association with severe injury, followed by systolic blood pressure. The differences between CareFlight Triage, Simple Triage and Rapid Treatment, and modified Simple Triage and Rapid Treatment were not dramatic, with sensitivities of 82% (95% confidence interval [CI] 75% to 88%), 85% (95% CI 78% to 90%), and 84% (95% CI 76% to 89%), respectively, and specificities of 96% (95% CI 94% to 97%), 86% (95% CI 84% to 88%), and 91% (95% CI 89% to 93%), respectively. Both forms of Triage Sieve were significantly poorer predictors of severe injury. Conclusion: Of the physiologic variables used in the triage algorithms, the Motor Component of the Glasgow Coma Scale and systolic blood pressure had the strongest association with severe injury. CareFlight Triage, Simple Triage and Rapid Treatment, and modified Simple Triage and Rapid Treatment had similar sensitivities in predicting critical injury in designated trauma patients, but CareFlight Triage had better specificity. Because patients in a true mass casualty situation may not be completely comparable with designated trauma patients transported to emergency departments in routine circumstances, the best triage instrument in this study may not be the best in an actual MCI. These findings must be validated prospectively before their accuracy can be confirmed. [Garner A, Lee A, Harrison K, Schultz CH. Comparative analysis of multiple-casualty incident triage algorithms. Ann Emerg Med. November 2001;38:541-548.]

Introduction

The medical management of a major multiple-casualty incident (MCI) revolves around victim triage. Accurately identifying patients who will substantially benefit from early scene intervention or transport to definitive care may be the most important medical function at an MCI.1 However, in the setting of a major MCI, these patients are typically in the minority, with most persons being either uninjured, mildly injured, or deceased.2 Triage systems used in MCIs must therefore allow rapid identification of the critically injured without the need for detailed examinations of all involved persons.

Physiologic systems have been favored in the MCI setting because they aim to identify patients with current instability. Anatomic and mechanism of injury-based systems identify patients who have the potential to deteriorate; the triage priority is therefore based on potential, rather than actual, instability. This may result in a tendency to overtriage patients, thereby overwhelming the system.3 Physiologic systems, however, provide a snapshot of the patient's stability at the instant of triage and are based on the assumption that triage will be an ongoing process with frequent reassessments. Patients who are initially physiologically stable but deteriorate will therefore be identified in subsequent triage rounds.

Several systems have been advocated as triage tools designed to enable the rapid identification of critically injured persons from large numbers of patients who do not have immediately life-threatening injuries in an MCI.

The Triage Sieve methodology4 (Figure 1) has been widely advocated in the United Kingdom and has been adopted in parts of Australia.The physiologic variables used in Triage Sieve to stratify patients are respiratory rate and either capillary refill or heart rate, depending on the ambient weather and temperature conditions.

The Simple Triage and Rapid Treatment algorithm (Figure 2) is used widely in North America.Simple Triage and Rapid Treatment initially used the ability to obey commands, respiratory rate, and capillary refill to assign a triage category. Modifications were later recommended that substituted palpability of the radial pulse for capillary refill because data suggested it to be more reliable.5

The CareFlight Triage (Figure 3) algorithm assesses the ability to obey commands, the presence of respirations, and the palpability of the radial pulse.It differs from modified Simple Triage and Rapid Treatment in that there is no respiratory rate assessment, and level of consciousness is assessed first.

There are no published reports or studies addressing the accuracy of these systems. The aim of this study was to retrospectively determine the association between the physiologic variables used in these triage systems, both in isolation and when combined together as an algorithm, with severe injury requiring immediate life-saving intervention or urgent transport.

Section snippets

Materials and methods

Consecutive trauma patients presenting to the emergency departments of 2 trauma centers in New South Wales, Australia, were retrospectively identified from the hospital trauma registries. All patients transported in the calendar year of 1994 were included. Patients from later years could not be included because, starting in 1995, ambulances stopped collecting patient data on the basis of the Trauma Score and began using the Triage-Revised Trauma score. Because the new system did not use

Results

There were 1,192 patients who met the study inclusion criteria. Forty-eight patients were excluded because the ambulance case sheets had not been filed in the patients' medical record or the data were incomplete, leaving 1,144 patients who were included in the data analysis. Sixty-five percent of the sample were men, 35% were women, and there were 38 (3.4%) deaths. The median age of the sample population was 33 years (interquartile range, 21 to 53 years). Mechanism of injury is presented in

Discussion

The physiologic predictors with the strongest association with critical injury were the Motor Component of the Glasgow Coma Scale and systolic blood pressure in this population of designated adult trauma patients. This finding is similar to the findings of other studies that examined the relationship between physiologic variables and severe injury,10, 11 particularly the utility of a measure of level of consciousness.12, 13, 14 The odds ratios were high for the Motor Component of the Glasgow

Acknowledgements

Author contributions: AG conceived the study and all authors were involved in study design. AG performed the data abstraction. AG and KH managed the data, including quality control. AL provided statistical advice on study design and analyzed the data. AG drafted the manuscript and all authors contributed substantially to its revision. AG, KH, and CHS take responsibility for the paper as a whole.

We thank the trauma registries of Nepean and Westmead Hospitals for their assistance and Jack Chen

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    *

    Author contributions are provided at the end of this article.

    **

    Address for reprints: Alan Garner, MSc, NRMA CareFlight, PO Box 159, Westmead 2145, Australia; E-mail [email protected].

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