Elsevier

Resuscitation

Volume 81, Issue 9, September 2010, Pages 1142-1147
Resuscitation

Clinical paper
Testing the validity of the ATLS classification of hypovolaemic shock

https://doi.org/10.1016/j.resuscitation.2010.04.007Get rights and content

Abstract

Aim

The Advanced Trauma Life Support system classifies the severity of shock. The aim of this study is to test the validity of this classification.

Methods

Admission physiology, injury and outcome variables from adult injured patients presenting to hospitals in England and Wales between 1989 and 2007 and stored on the Trauma Audit and Research Network (TARN) database, were studied. Patients were divided into groups representing the four ATLS classes of shock, based on heart rate (HR) systolic blood pressure (SBP), respiratory rate (RR) and Glasgow Coma Score (GCS). The relationships between variables were examined by classifying the cohort by each recorded variable in turn and deriving the median and interquartile range (IQR) of the remaining three variables. Patients with penetrating trauma and major injuries were examined in sub-group analyses.

Results

In blunt trauma patients grouped by HR, the median SBP decreased from 128 mm Hg in patients with HR < 100 BPM to 114 mm Hg in those with HR > 140 BPM. The median RR increased from 18 to 22 bpm and the GCS reduced from 15 to 14. The median HR in hypotensive patients was 88 BPM compared to 83 BPM in normotensive patients and the RR was the same. When grouped by RR, the HR increased with increasing RR but there were no changes in SBP.

Conclusion

In trauma patients there is an inter-relationship between derangements of HR, SBP, RR and GCS but not to the same degree as that suggested by the ATLS classification of shock.

Introduction

Unrecognised hypovolaemic shock is the commonest cause of preventable death following trauma.1 In the early stages of trauma resuscitation, the recognition of hypovolaemia is usually based on an estimation of volume of blood loss from injuries sustained and/or from traditional vital signs.

The Advanced Trauma Life Support (ATLS) system2 has been devised for the initial management of patients with major trauma and has become internationally accepted. Its manual classifies the degree of hypovolaemic shock in adults. A simplified version is shown in Table 1.

While ATLS offer this as a guide only, their classification is widely used in practice and has been reproduced (sometimes with minor variations) in many other articles and guidelines on the management of trauma.3, 4, 5, 6

This classification is unreferenced and we found no evidence to fully support it. In addition there are other influences on vital signs. Heart rate and blood pressure may be affected by age, anxiety, pain, medication, raised intracranial pressure, core temperature, and spinal cord injury. Respiratory rate may be raised in chest injury and conscious level may be reduced in patients with brain injury.

Our research question was to test the validity of the ATLS classification of shock by comparing it with the initial ED physiological data recordings of injured patients held in the Trauma Audit and Research Network (TARN) database.

Section snippets

Data and inclusion criteria

Cases included were adults aged 16 or over presenting between 1989 and 2007, and submitted by participating hospitals to TARN. Eligible patients are those who sustain injury resulting in immediate admission to hospital for three days or longer, admission to an intensive care or a high dependency unit, transfer for specialist care or death within 93 days. TARN excludes patients over 65 years with isolated fracture of the femoral neck or pubic ramus and those with single uncomplicated limb

Results

107,649 adult patients injured by blunt trauma were entered into the TARN database between 1989 and 2007.

Times from incident to arrival in the ED are only available for 40% of the patients. The median time is 1.08 h (IQR 0.72–1.83)

Discussion

In this trauma registry there is an association between raised HR, lowered SBP and raised RR but not to the degree indicated by ATLS. The values given in the ATLS classification of shock (Table 1) do not appear accurate from this analysis.

It is clear that tachycardia is an indicator of severity as shown by increasing ISS and increasing mortality with an increasing HR, especially in blunt trauma. However, although the SBP decreased and the RR increased with increasing HR, this was not to the

Conclusion

In a large trauma registry there is an association between raised HR, lowered SBP and raised RR but not to the degree indicated by the ATLS classification of shock.

A tachycardia after injury is associated with increased mortality but the absence of tachycardia does not exclude shock as significant blood loss can be associated with a bradycardia.

The diagnosis of shock in the emergency department is a complex clinical diagnosis that should be based on physiological measurements, the injuries

Conflict of interest statement

None.

References (17)

There are more references available in the full text version of this article.

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A Spanish translated version of the abstract of this article appears as Appendix in the online version at doi:10.1016/j.resuscitation.2010.04.007.

1

On behalf of the Trauma Audit and Research Network (TARN).

2

Current address: Tigh-Fraoich, Dervaig, Tobermory, Isle of Mull, PA75 6QW, UK.

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