The Royal Marsden Hospital Manual of Clinical Nursing Procedures - Lisa Dougherty [505]
Abnormal flexion 3 Decorticate posturing (flexion of arms, hyperextension of legs) spontaneously or in response to noxious stimuli
Extension 2 Decerebrate posturing (limbs extended and internally rotated) spontaneously or in response to noxious stimuli
None 1 No response to noxious stimuli. Flaccid limbs
Aucken and Crawford (1998), Carlson (2002a).
Assessment of level of consciousness
Assessment using the GCS involves three phases (Teasdale and Jennett 1974).
1. Eye opening.
2. Evaluation of verbal response.
3. Evaluation of motor response.
Evaluation of eye opening
Eye opening indicates that the arousal mechanism in the brain is active. Eye opening may be: spontaneous; to speech, for example spoken name; to painful stimulus; or not at all. Arousal (eye opening) is always the first measurement undertaken when performing the GCS, as without arousal, cognition cannot occur (Aucken and Crawford 1998). It must, however, be remembered that swollen or permanently closed eyes (e.g. after tarsorrhaphy surgery in which the upper and lower eyelids are partially or wholly joined to protect the cornea; Martin 2003) will not open and do not necessarily indicate a falling conscious level.
Evaluation of verbal response
Orientated: the patient is aware of self and environment.
Confused: the patient’s responses to questions are incorrect and patient is unaware of self or environment.
Inappropriate words: the patient responds using intelligible words which are unsuitable as responses.
Incomprehensible: the patient may moan and groan without recognizable words.
Absent: the patient does not speak or make sounds at all.
The absence of speech may not always indicate a falling level of consciousness. The patient may not speak English (though they can still speak), may have a tracheostomy or may be dysphasic. The patient may have a motor (expressive) dysphasia, and therefore be able to understand but be unable to find the right word, or a sensory (receptive) dysphasia, being unable to comprehend what is being told to them (Aucken and Crawford 1998, Shah 1999). At times patients with expressive dysphasia may also have receptive problems; therefore it is important to make an early referral to a speech and language therapist. The nurse should also bear in mind that some patients may need a lot of stimulation to maintain their concentration to answer questions, even though they can answer them correctly. It is, therefore, important to note the amount of stimulation that the patient required as part of the baseline assessment (Aucken and Crawford 1998). If a patient cannot follow the instruction due to a language barrier or unconsciousness, observe spontaneous movements and note how strong they appear. Then, if necessary, apply painful stimuli.
Evaluation of motor response
To obtain an accurate picture of brain function, motor response is tested by using the upper limbs because responses in the lower limbs reflect spinal function (Aucken and Crawford 1998). The patient should be asked to obey commands; for example, the patient should be asked to squeeze the examiner’s hands (both sides) with the best motor response recorded. The nurse should note power in the hands and the patient’s ability to release the grip. This is because some patients with cerebral dysfunction, for example those with diffuse brain disease, may show an involuntary grasp reflex where stimulation of the palm of their hand causes them to grip (Aucken and Crawford 1998). If movement is spontaneous, the nurse should note which limbs move, and how, for example whether the movement is purposeful.
Response to painful stimulus may be:
localized: the patient moves the other hand to the site of the stimulus
flexor: the patient’s limb flexes away from pain
extensor: the patient’s limb extends from pain
flaccid: no motor response at all.
(Aucken and Crawford 1998, Shah 1999)
Procedure guideline 12.9 Neurological observations and assessment
Essential equipment
Pen torch
Thermometer