Diagnosis

In the initial assessment of coma, it is common to judge by
spontaneous actions, response to vocal stimuli and response to
painful stimuli; this is known as the AVPU (alert, vocal stimuli,
painful stimuli, unconscious) scale. The most common scales
used for rapid assessment are:
1. The Glasgow Coma Scale (GCS), which aims to record the
conscious state of a person, in initial as well as continuing
assessment. When a patient is assessed and the resulting score is
either 14 (original scale) or 15 (the more widely used modified or
revised scale), this means ‘normal’; while if a patient is unable to
voluntarily open their eyes, does not have a sleep-wake cycle, is
unresponsive in spite of strong sensory (painful) or verbal
stimuli and who generally scores between 3 to 8 on the Glasgow
Coma Scale, (s)he is considered to be in coma.
2. Pediatric Glasgow Coma Scale: The Pediatric Glasgow Coma
Scale (PGCS) is the equivalent of the Glasgow Coma Scale used to
assess the mental state of adult patients. As with the GCS, the
PGCS comprises three tests: eye, verbal and motor responses.
The three values separately as well as their sum are considered
(Holmes 2005). The lowest possible PGCS is 3 (deep coma or
death) whilst the highest is 15 (fully awake and aware) (Holmes
2005).
Diagnosis of coma is simple; but determining the cause of the
underlying pathology may prove to be challenging. As in those
with deep unconsciousness, there is a risk of asphyxiation as
control over the muscles in the face and throat is diminished, so
those in a coma are typically assessed for airway management,
nasopharyngeal airway or endotracheal intubation to safeguard
the airway (Formisano 2004).
Following the previous assessment patients with impaired
consciousness can be classified according to their degree of
consciousness disturbance into lethargic, stuporous or comatose.
Lethargy resembles sleepiness, except that the patient is
incapable of becoming fully alert; these patients are conversant
24 | Critical Care in Neurology
and attentive but slow to respond, unable to adequately perform
simple concentration tasks such as counting from 20 to 1, or
reciting the months in reverse.
Stupor means incomplete arousal to painful stimuli, little or no
response to verbal commands, the patient may obey commands
temporarily when aroused by noxious stimuli but more often
only by pain.
Coma is the absence of verbal or complex motor responses to
any stimulus (Stevens 2006).