How should head injured patients be assessed and classified?

2.1 Assessing the Patient

The approach to management of head injuries which depended on taking urgent action following the detection of deterioration has been superseded by one based on utilisation of pre-emptive investigation to detect lesions before they lead to neurological deterioration. The management of individual head injured patients, and the formulation and application of guidelines depends upon the use of a widely accepted and applicable method of assessment and classification of the so-called 'level of consciousness'. This provides the most useful indication of the initial severity of brain damage and its subsequent changes over time.

The Glasgow Coma Scale²¹ and its derivative the Glasgow Coma Score²² are used widely for assessing patients both before and after arrival at hospital.^23-25 Extensive studies have supported their repeatability,^26-29 validity,²², ^30-34 and other clinimetric properties.³⁵ Evidence level III

The management of head injured patients should be guided by clinical assessments and protocols based on the Glasgow Coma Scale and Glasgow Coma Score.

The Glasgow Coma Scale is difficult to apply to the young (under 5 years) child. Although modifications exist,36 great care needs to be taken with its interpretation and this should be done by those with experience in the management of the young child.

The AVPU (Alert, Verbal, Painful, Unresponsive) system can provide a rough guide to whether patients need airway protection, but full assessment will still be required.³⁷, ³⁸

2.2 The Glasgow Coma Scale and Coma Score

The Glasgow Coma Scale provides a framework for describing the state of a patient in terms of three aspects of responsiveness: eye opening, verbal response, and best motor response, each stratified according to increasing impairment. In the first description of the Scale for general use, the motor response had only five options, with no demarcation between 'normal' and 'abnormal' flexion. The distinction between these movements can be difficult to make consistently ²⁶, ²⁷ and is rarely useful in monitoring an individual patient but is relevant to prognosis and is therefore part of an extended six option scale used to classify severity in groups of patients.³⁰, ³², ³⁹

The Glasgow Coma Score is an artificial index; obtained by adding scores for the three responses.²² The notation for the score was derived from the extended scale, incorporating the distinction between normal and abnormal flexion movements, producing a total score of 15 (see Table 1). This score can provide a useful single figure summary and a basis for systems of classification, but contains less information than a description separately of the three responses.

The three responses of the original (1974) scale, not the total score, should therefore, be of use in describing, monitoring and exchanging information about individual patients. The guideline development group recommends that the progress of the patient should be recorded on a chart, incorporating the Glasgow Coma Scale and other features. An example chart which is widely used is included at Annex 2.

Examination of the cranial nerves, in particular pupil reactivity, and neurological examination of the limbs, in particular the pattern and power of movement, provide supplementary information about the site and severity of local brain damage. Information about mechanisms of injury, other injuries and complications should be also recorded.

Classification of head injured patients can be made using information from the Glasgow Coma Scale or Score. In view of the widespread use of both systems, the recommendations in this guideline are framed in both terms where appropriate.

Monitoring and exchange of information about individual patients should be based on three separate responses of the Glasgow Coma Scale.

If a total score is recorded or communicated, it should be based on a sum of 15, and to avoid confusion this denominator should be specified.

A standard chart should be used to record and display assessments, including the Glasgow Coma Scale, pupil size and reaction and movements of right and left limbs.

Table 1

The Glasgow Coma Scale and Score

Feature							Scale Responses		Score Notation
Eye opening							Spontaneous		4
							To speech		3
							To pain		2
							None		1
Verbal response							Orientated		5
							Confused conversation		4
							Words (inappropriate)		3
							Sounds (incomprehensible)		2
							None		1
Best motor response							Obey commands		6
							Localise pain		5
							Flexion	Normal	4
								Abnormal	3
							Extend		2
							None		1
TOTAL COMA ‘SCORE’									3/15 - 15/15