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The Glasgow Coma Scale and otherneurological observationsNS289 Watefhouse C (2005) The Glasgow Coma Scale and other neurological observations. NursingStandard. 19,33, 56-64. Date of acceptance: October 14 2004.

SummaryThe primary tool used by nurses to assess a patient's neurologicalstatus is the neurological observation chart incorporating theGlasgow Coma Scale. This article explains the correct use of thechart and how to interpret the findings.

AuthorCath Waterhouse is lecturer practitioner, Royal HallamshireHospital, Sheffield. Email: Cath.waterhouse@sth.nhs.uk

KeywordsGlasgow Coma Scale; Neurological assessment; Observations;Vital signs

These keywords are based on the subject headings from the BritishNursing Index, This article has been subject to double-blind review.For related articles and author guidelines visit the online archive atwww.nursing-standard.co.uk and search using the keywords.

Introduction

Aims and intended learning outcomes

This article aims to raise awareness of basicneurological observations, namely the GlasgowComa Scale (GCS), pupil reaction, limb responsesand vital signs. It should be of value to all nurseswho care for patients at risk of neurologicaldeterioration. It explains how to complete theneurological observation chart, which includesthe GCS, accurately, safely and consistently. Afterreading this article you should be able to:

• Outline the rationale for using the GCS.

• Assess a patient's level of consciousness byevaluating three behavioural responses: eyeopening, verbal response and motor response.

• Perform a neurological assessment, using theGCS., pupil reaction, limb responses and vitalsigns, and interpret the findings.

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Many patients are admitted to neurosurgical unitsfrom general clinical areas such as medical units oraccident and emergency departments. Nursesworking in these areas need to be able to perform abasic neurological assessment accurately andunderstand the significance of tbe findings.Accurate assessment and prompt action whenneeded can improve the eventual outcome, notj ust in terms of survival but also by minimising thedegree of residual neurological deficit.

The neurological observation chartincorporating the GCS is well established bothnationally and internationally (Teasdale andJennett 1974)as the primary tool used by nursesto make quick, repeated evaluations of severalkey indicators of neurological status (Auken andCrawford 1998):

• Level of consciousness (GCS).

• Pupil size and response to light.

• Limb movements (motor and sensory function).

• Vital signs.

Recently published guidelines for themanagement of patients with head injuries(National Institute for Clinical Excellence (NICE)2003 ] stipulate the use of the GCS for assessmentand classification of all head-injured patients.

Although there have been some useful articleson the GCS tool (Ellis and Cavanagh 1992, Shah1999, Woodward 1997a, b, c, d), benchmarkingstandards have relied on consensus and theexpertise of skilled nurses from neuroscienceunits throughout the UK.

The layout and appearance of the neurologicalobservation chart incorporating the GCS will vary,depending on the trust in which you work.

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Obtain your iocat neurologicalobservation chart:

Identify which section makes up the GCS.Note what other observations are containedwithin the form.Consider the relevance of the observationsto determining the level of consciousness.

1 he CJCS was originally developed to monitor theprogress of patients with an acute head injury;however, it is now generally considered to be auseful too! for assessing all paiients who arepotentially at risk of neurological deterioration,regardless of their primary pa:hology. The GCS isdesigned to assess the integrity of normal brainfunction and is the best tool for consistentlyassessing a patient's level of consciousness {Aukenand Crawford 1998).

However, the apparent 'simplicity' of the toolleaves it open to misunderstanding and misuse(Addison and Crawford 1999 )/Quick and easyto use' does not denote msignificant (Shah 1999).In practice, although practitioners may be able totick the right 'boxes' on the chart, few nursesappreciate the mechanism underpinning theassessment, which enables them to actappropriately when the patient's conditionchanges. Not infrequently, a patient's changingneurological state is not identified early enough tobe either life-saving or prevent further braininsults (Ellis and Cavanagh 1992).

ecall a patient that you havenursed recently who was havingneurological observations carried out. •[

Identify the potential causes of a reducedlevel of consciousness in the patient. It isquite possible that a patient's low level ofconsciousness is not an intracranial pressureproblem but is post-ictal or drugs-related,for example.Discuss these with a colleague and add fourother possible causes of a reduced level ofconsciousness.

as many of the markedstructures on Figures 1 and 2 as youcan without using a textbook. Check andcomplete the exercise using a general anatomy'and physiology textbook, su:h as Martini(2001) or Tortora and Anagnostakos (2003).

FIGURE 1

Cross-section of the brain

FIGURE 2

Anatomy and physioloqy

The skull is a hard, unyielding structurecontaining brain parenchyma and cerebrospinalfluid (CSF), interstitial fluid and arterial andvenous blood. There is little 'tree space' toaccommodate expanding lesions such as a bloodclot, tumour or oedema. Therefore, any mcreasein the volume of one of the primary componentswill, unless compensated for by a correspondingreduction in the volume of another component,lead to an increase in pressure inside the skull.This will compress the blood vessels and severelycompromise blood flow and perfusion to thecerebral tissues (Hickey 2002 , Lindsay and Bone2004). Total intracraniat volume = brain + CSF +blood. Possible causes of raised intracranialpressure (ICP) are listed in Box 1.Consciousness Consciousness has been definedas 'a general awareness of oneself and thesurrounding environment, it is a dynamic statethat is subject to change' (Hickey 2002).Consciousness consists of two components:• Arousal or wakefulness, which is largely a

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function of a specialised group of neuroneswithin rhehrLilnstem known as the reticularactivating system (RAS).

• Awareness and cognition, which is a functionofthe highercortical areas of the cerebralcortex activated via the thalamic portion oftheRAS.

The Glasgow Coma Scale

The score derived from the GCS provides anessential baseline for comparison with futurescores to determine whether a patient'sneurological condition is improving, static ordeteriorating. Its graphic, visual format ensuresuniformity and gives a quick, concise, visualinterpretation of the patient's level ofconsciousness, and hence neurological status overa periodof time{Shah 1999).

The GSC evaluates three key categories ofbehavioiirthatmostclosely reflect activity in thehigher centres of the bram: eye opening., verbalresponse and motor response. These enable us todetermine whether the patient has cerebraldysfunction. Within each category, each level ofresponse is allocated a numerical value, on a scaleof increasing neurological deterioration andbrain insult. The lowest score that a patient canachieve is 3, indicatmg total unresponsiveness.The maximum score is 15, mdicatingan awake,alert and fully responsive patient (Table 1)(NICE 2003).

The GCS was designed specifically as a tool fordetectingand monitoringchangesina patient's

Causes of raised intracranjal pressure

• ExtraduraUubduralorintracGrebralhaematoma

• Cerebral oedema (primary and secondary) occurring as a responseto injury

• Obstructed venous return due to a thrombus or embolism

• Hypercapnia (excess carbon dioxide in the blood) causesvasodilation of cerebral vessels, and hence a rise in intracranialpressure

• Tumour and its associated oedema resulting from compressionof surrounding tissue and increasing permeability of thecapillary walls

• Hydrocephalus - increase in the volume of cerebospinal fluid

• Metabolic factors - renal and hepatic disease, electrolyte imbalanceresulting in diffuse cerebral oedemacHjckey 2002)

neurological condition. In practice, this meansthat you should imagine that you are "taking thepatient's photograph' and then record what yousee in it, thereby avoiding the temptation to adjustthe information to take into account either thepatient's medical history or any pre-existingharriersto communication or language. Anotherpotential error is failure to stimulate patientssufficiently to get a true reflection ot theirneurological responses [Addison and Crawford1999, Lower 1992).

Unless you have a firm baseline forcomparison, you are not going to recognise whenthe patient's neurological condition deterioratesand will not be able to react appropriately to therising ICP {Lower 1992).How to assess best eye response This directlyassesses tbe functioning of the brainstem anddemonstrates to the assessor that the RAS hasbeenstimulatedand the patient is aware of his orhtT environment. Note that eye opening is notalways an indication of intact neurologicalfunctioning. Patients who have been assessed asbeing in a persistent vegetative state will opentheireyes(they also track movement) as a directreflex action generated by tbe RAS.Eye opening spontaneously - scores 4 T h i s i srecorded when the patient is seen to he awake,with eyes open. Approach the patient. If aware ofyour presence, the patient should open his or hereyes without the need for speech or touch.Eye opening to verbal command - scores 3Again, this observation is made withouttouching the patient. Speak to tbe patient in anormal voice first. Then, if necessary, graduallyraise your voice. In some cases the patient wiltrespond better to a familiar family voice.fyeopem/ifftopo/n-sco/-es2Initially, to avoidunnecessary distress, simply touch or shake thepatient's shoulder. If there is no response to thismanoeuvre, a deeper stimulus is required, and aperipheral stimulus must be applied. Before anystimulus is applied, it Is essential to explain to thepatient and relatives exactly what you are goingto do and why, apologising for the need to hurtthe patient (even if he or she appears to beunconscious).

At this stage of the assessment it is importantto use a peripheral painful stimulus, as theapplication of a centra! painful stimulus tends tomake patients close tbcir eyes and induces agrimacing effect (Teasdale and jennett 1974),which is not the response you are trying toachieve.

Peripheral stimulation involves applyingpressure with a pen to the lateral outer aspect oftbe second or third finger, rotating the point ofstimulation around on each assessment. Painshould be applied gradually, up to a maximum often seconds, and then released. This can be

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repeated, btit the patient should suffer onlymomentarily and not experience long-term pain(Fairley and Cosgrove 1999). If the desiredresponse is still not observed it is itnportant toseek a second opinion.

Under no circumstances should sternalrubbing or nail-bed pressure be used, as thiscan result in unnecessary bruising andprolonged residual discomfort (Fairley andCosgrove 1999).yVoeyeopen/ng-scoresJThis score is recordedwhen no response to a painful stimulus isobserved. This should only be recorded when thenurse is satisfied that a sufficient stimulus wasused. Remember that inadequate stimulationwill lead to an inaccurate assessment.Points to note• If tbe patient's eyes are closed as a result of

swelling or facial fractures, this is recordedas 'C" on the chart. In such cases it isimpossible to perform an accurateassessment of the patient's level of arousal orawareness.

• A good sensitive indicator of neurologicalchange is the patient's level of consciousness -is the patient becoming more difficult torouse? Patients will often become increasinglyrestless, or a previously restless patient maybecome atypically quiet.

• Even if the patient is thought to be in a chronicstate of long-term coma, his or her eyes may bewide open but he or she will not be aware ofhim or herself or the environment. One of thecriteria for diagnosing persistent vegetativesyndrome is that the patient develops asleep-wakefulness cycle (Berrol 1986, jennettand Teasdale 1977]. Remember only recordwhat you see.

UReflect on and write down howyou would carry out the (iyeopening part of the Glasgow ComaScale assessment.

Observe a colleague (or ask him or her todescribe his or her practice) and discuss, andnote, any variations in approach.Identify where eliciting an eye openingresponse is difficult or impossible, yetunrelated to conscious level. How shouldthese situations be mana^jed?

How to assess best verbal response Best verbalresponse provides the practitioner withinformation about the patient's speech,comprehension and functioning areas of thehigher, cognitive centres of the brain, and reflects

the patient's ability to articulate and express areply.OWentoferf-scoresSThis assesses orientation totime, place and person. Patients must be able totell you:• Whothey are (their name).

• Where they are and why (in which town or cityand tbe name of the hospital).

• The current year and month (avoid using theday of the week or the date).

if all three questions are answered correctly, thepatient may be classed as orientated.Confi/serf-scores 4 If one or more of the abovequestions are answered incorrectly, the patientmust be recorded as being confused. If the patienthas recently been transferred from anotherhospital, some degree of disorientation isunderstandable, but remember that such subtleorientation loss can be a good early indicator ofneurological deterioration (Frawley 1990).

At the same time, it is important to attempt tore-orientate patients by correcting all wronganswers. Reassure them, and ask them ro try toremember for tbe next time you ask. Typically,patients who are deteriorating will loseorientation to time, place and person - in thatorder (Shab 1999).

Inappropriate words - scores3 C:ompletelyunderstandable conversation is usually absent orextremely limited. Patients offer words ratherthan sentences, which make little sense in tbecontext of the questions. Sometimes these words

Glasgow Coma Scale and Score (NICE 2003)

Feature

Best eye response

Best verbal response

Best motor response

Response

Open spontaneously

Open to verbal command

Open to pain

No eye opening

Orientated

Confused

Inappropriate words

Incomprehensible sounds

No verbal response

Obeys commands

Localising pain

Withdrawal from pain

Flexion to pain

Extension to pain

No motor response

Score

4

3

2

1

5

4

3

2

1

6

5

4

3

21

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are communicated as obscenities. Patients with amotor dysphasia are often difficult to assess asthey are frequently unable to utter the words theywish to say, or are unable to thmk of the righrwords to express themselves. Patients may alsocontinue for an exceptionally long period,repeating a phrase or particular words - this isknown as persevL'ration (Patten I99S).Incomprehensible sounds-scores 2 Althoughthe patient's response can follow verbalquestioning, more often it comes in directresponse to a painful stimulus. The patientresponds to speech or painful stimulation with nounderstandable words, and may only be able toproducemoaning, groaning or crying sounds. Ifthe patient has sustained damage to the speechcentres in the brain and is unable to talk, butremains aware and alert, the score must stili berecorded as 2, unless alternative cotnmunicationdevices such as writing, computers or light writerscan be used.

No verbal response-scores 1 The patient isunable to produce any speech or sounds inresponse to speech or painful stimuli.Points to note• If the patient is unable to respond because of

the presence of a tracheostomy orendotracheal tube, this should be recorded onthe chart as a letter'T\

• If the patient is dysphasic, this should berecorded on the chart as a letter 'D'.

• Therecordingofaccuratebaselineobservations is the most important element ofthe tool as it allows the practitioner to identifythe earliest subtle signs. For this reason, everyassessor must apply the same stimulus in thesame manner and question each patient in thesame way (Frawley 1990).

• One criticism of the GCS tool (Williams1992) is that patients cannot be adequatelyassessed it they have any kind ofcommunication difficulties related to age(cannot be used for patients under five yearsold), language (no comprehension of theEnglish language), or any pre-existingpathology that might affect speech such aslearning difficulties or stroke. It is importantnot to attempt to adapt, change or write onthe chart to "fit in' with the patient-youmust only record what you see. Informationgathered from the family, such as thepatient's preferred name ur details of anypre-existing deficits, may be invaluable inmaking an accurate assessment.

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From your experience, whatbarriers unrelated to alteredconsciousness may prevent you fromobtaining orinterpreting a verbal response from a patientf

How to assess best motor response Best motorresponse tests the area of the brain that identifiessensory input and translates this into a motorresponse. The best possible motor response isbeing able to obey simple commandsconvincingly, and is the highest level of motorresponse (Frawley 1990).0/?eyscommortcfe-sco/'es6The patient canaccurately respond to instructions. Ask thepatient to perform a couple of differentmovements, for example, stick out his or hertongue, raise his or her eyebrows, show his or herteeth and hold up his or her thumb. If askingpatients to 'squeeze my fingers', ensure that youalso ask them to iet go', to discount a primitivegrasp reflex. It is good practice to have patientsobey two different commands, and at the veryleast they should obey the same command twice(Lower 1992}.

Localising pain-scores 5TWis is the response to acentral painful stimulus. It involves the highercentres of the brain recognising that something ishurting the patient and trying to remove that painsource (Jennett and Teasdale 1 977). A painfulstimulus should be applied only when the patientshows no response to verbal instruction, and neednot be applied if the patient is already localising,for example, by pulling at an oxygen mask ornasogastrictube.

To be classified as localisation, patients mustmove their hand to the point of stimulation,bringing the hand up towards the chin, across themidline, in an obvious, co-ordinated attempt toremove the cause of the pain. It is useful to startwith the arm in a 30° flexed position to minimiseany anomalies when assessing abnormal flexionor extension.

Three methods of applying a central painfulstimulus have been recognised by the NationalNeuroscience Benchmarking Group:1. Supra-orbitat pressure-This was identifiedas the 'gold standard' but must only be usedwhen the practitioner has been trained to apply itcorrectly. Just below the inner aspect of theeyebrow is a small notch through which a branchof the facial nerve runs. The nurse's hand rests onthe head of the patient, and the flat of the thumbor the knuckle is placed on the supra-orbitalridge under the eyebrow. Pressure is graduallyincreased for a maximum of 30 seconds. This isconrraindicated if there is any orbital damage orskull fracture (in which case the 'trapezius

NURSING STANDARD

squeeze' is a suitable alternative (Ellis andCavanagh 19921).2. Jaw margin pressure Pressure is applied at theangle of the jaw. Rest the flat of the thumb againstthecornerof the maxillary ami mandibularjunction and apply gradually increasing pressurefora maxinnnn of 30seconds.

3. The trapezius squeeze - The trapezius muscleextends across the back of the shoulders from themiddle of the neck. Hold the muscle between thethumb and forefingers and apply graduallyincreasing pressure fora maximum of 30seconds. The trapezius muscle has both a sensoryand a motor component and there is a risk ofeliciting a spinal reflex on stimulation.

Other methods of applying a central painfulstimulus are not recommended because they canelicit a peripheral reflex response only.Withdrawal from pain - scores 4 In response toa central painful stimulus, patients will bendtheir arms at the elbow as a normal flexionreflex action, but fail to locate the source of thepain.

Flexion to pain-scores 3Thh is also known asdecorticate posturing. It occurs when there is ablock in the motor pathway bL'tween tbe cerebralcortex and the brain stem. It is a much slowerresponse to a painful stimulus, and can berecognised by the patient flexing the upper armand rotating the wrist. Often tbe thumb comesthrough the fingers.

£jffens/onto/7Cf/n-scores2T his is also known asdecerebratc posturing. It occurs when the motorpathway is blocked or damaged within thebrainstem, and is characterised by straighteningof the elbow and internal rotation of the shoulderand wrist. Often the legs are also in extension,with the toes pointingdownwards.yVomoto/'response-scoresJ The patient's brainis incapable of processing any sensory input ormotor activity, and tbe patien: is therefore unableto move at all in response to a painful stimulus.Before recording 'none', ensure that adequatestimulation has been applied. Note that a patientmay be unresponsive because of local disease or1 n ] u ry.

Points to note> Always record the best arm response using a

central painful stimulus: when assessing motorresponse it is the brain that is being assessed,not the spinal response. Spmal reflexes maycause limbs to flex briskly and can even occurin patients wbo have been certified brainstemdead (Stewart 1996).

• Nurses should also beawa'cof tbeir own non-verbal behaviour, as patients may simplymimic what they see, giving rise rointerpretation error.

NURSING STANDARD

Discuss with a medical colleagueand a nursing colleague, the conditions,other than serious reduction in level ofconsciousness, that may contribute to apatient becoming unable to move their limbs.

General notes

The level of consciousness is the most sensitiveindicator of neurological deterioration. Unlesstbe patient is receiving anaesthetic agents orsedatives, it should be possible to identifydeterioration using tbe GCS, before changes inpupils or vital signs occur.

A dererioration of 1 point in the motorresponse or an overall deterioration of 2 points intbe GCS score is clinically significant and must bereported immediately to a senior member of staff(Cree 2003, NICE 2003}. To ensure consistency,the same member of staff should carry out theassessment over a given sbift. At handover, tbereceivingnurse should observe how the GGSscore was obtained. Without sucb continuity,subtle yet significant alterations can be missed(Grant ef a/1990).

Patients will often give out subtle clues thatthey are deteriorating sucb as becoming lesscommunicative with slower responses,particularly relating to changes in theirbehaviour. The practitioner must be attentive tothese changes and document them in the patient'srecords. Lack of confidence in completing thechart can lead practitioners to be influenced bythe previous assessment (Watson etal 1992).Always ask a colleague to reassess if you areunsure of the procedure. The GCS was notintended to be used in isolation. It should be usedin coniunction with other aspects of theneurological assessment, such as pupil reaction,limb responses, temperature and vital signs(Addison and Crawford 1999).

Time out 7Consider the legal and ethicalaspects of causing direct pain to "~- -•patients when assessing the motor response,and the methods by which the pain stimulus isapplied. Discuss the key issues with yourcolleagues and reflect on their perceptions ofthese.

Pupil reaction

Pupil reaction is a very important observation asit gives the practitioner a 'window to view thebrain'andis the only way of monitoring the

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neurological status of a sedated patient. Table 2setsoutguidelinesfortheassessment of pupilreaction to light and the rationale for theprocedure.

Any changes in pupil reaction, shape or sizearea late sign of raised ICP. Sluggish or suddenlydilated unequal pupils are an indication thatoedema or haematoma is worsening and theoculomotor cranial nerve is being compressedthrough the foramen magnum. Urgentintervention at this stage can make a significantdifference to the patient's outcome. Rememberthat some patients may have a pre-existingophthalmic condition that produces aunilaterally dilated pupil, such as a cataract orlocalised injury.

A more subtle sign is constriction and dilationof the pupil w Ithout regard to light. The pupil isunable to sustain its constriction in the presenceof a bright light and re-diUites (referred to asunilateral hippus(Patten \99H)).

All of these signs are obvious danger signalsand must be reported to the medical teamurgently, as this is a medical emergency andpotentially life-threatening.Points to note• If both eyes are closed because of gross orbital

swelling, this is recorded with a letter ' C .

• Brisk pupils are recorded as'+', unreactivepupils as ' - ' and sluggish pupils as 'S'.

• A bright pen torch must be used - not anophthalmoscope.

• Minor inequalities in the size of the pupils aren{)rinal.

• It is not uncommon for healthy people to havepupils of unequal sizx.

• Very small pupils (1-2mm) may suggest the useof opiates, fentanyl or barbiturates.

• The use of eye drops, such as atropine,candilate the pupils.

Lirnbj;esponses

Evaluation of limb responses provides theassessor with detail of the geographicaldistribution of dysfunction, and is an importantconsideration when performing a fullneurological assessment of the patient (Lower1992). Each limb should be assessed separately.Ask patients to hold their arms out in front ofthem and observe for signs of weakness or 'drift'.Assess the legs by asking patients if they can pushand pull their feet towards the assessor, or askwhetherthey are able to raise their legs off thebed and hold them there briefly. A peripheralpainful stimulus needs to be applied to limbs thathave not been seen to move.

TABLE 2 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^MGuidelines for assessment of pupil reaction to

Procedure

Inform the patient, whether conscious or not,that you are going to look into his or her eyeswith a torch, and explain the procedure

Reduce the light from overhead lights to seeany pupil reaction

Wash hands thoroughly

Hold the patient's eyes open and note as abaseline the size, shape and equality of thepupils as an indication of brain damage

Hold one of the patient's eyes open, and move alight from the outer aspect of the eye towardsthe pupil. This should cause the eye to constnctquickly (direct light response)

Record unusual eye movements such asnystagmus or deviation to the side

Repeat tests on the opposite eye

(Mallett and Dougherty 2000)

ight

Rationale

Helps to reduce anxiety. Ensures, as far aspossible, that the patient consents to, andunderstands, the procedure

Enables a better view of the eye and reactionto a light stimulus

Prevents contamination of the eye and reducesthe risk of infection

Normal pupils are round, usually central andrange in diameter from 1.5mm to 6.0mm

To assess pupil reaction to light.A normal reaction indicates no lesion orpressure on the third cranial nerve or brainstemregulating the pupil reaction

To assess cranial nerve damage

To assess eguality of reaction and ensure thatall areas are functioning correctly

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Temperature

A patient's temperature may be elevated as aresult of infection; however, a patient who hassustained a severe head injury may have localiseddamage to the temperature-regulating centre inthehypothalamus. As the patient's temperaturerises, cerebral cell metabolisir produces excesscarbon dioxide, producing vasodilation of thecerebral blood vessels which compounds theexistingcerebral swelling.

Vital signs

The final warning is Cusbing's triad or reflex-aclassic set of clinical and physiological signs andsymptoms which indicate that the ICP isdangerously high and the patient is in danger of'coning' (cerebral herniation) which will rapidlylead to thedeatb of tbe patient. The reflex Is avery late sign and is characterised byhypertension, bradycardia and respiratoryirregularity.

Hypertension Typically the p.itient will have anelevated systolic blood pressure combined with awidening pulse pressure. This causes systemicvasoconstriction and hypertension.• As the ICP increases, arterial blood cannot get

through to perfuse the brain. Mean arterialpressure (MAP) minus ICP equals cerebralperfusion pressure (CPP) (MAP - ICP = CPP).

When CPP tails below a critical threshold, bloodcannot enterthe brain.• As systolic blood pressure increases, diastolic

blood pressure remains relatively unchanged,resulting in a widening pulse pressure.

Bradycardia The heart rate may drop as low as35-50 beats per minute. This allows each systoleto pump more blood at a higher pressure, forcingblood into the brain during tbe peak arterialsystolic blood pressure.Respiratory irregularity Pressure on therespiratory centres in the lower pons and uppermedulla causes impairment of respiratorypatterns. The following patterns may be seen:

• Cheyne-Stokes breathing.

• Hyperventilation blows off carbon dioxideand constricts cerebral vessels in an attempt tolower ICP.

• Cluster breathing-period; of rapid irregularand noisy breathing separated by apnoeicspells.

Frequency of observations

The NICE (2003) guidelines are specificallyaimed at managing patients in accident and

emergency departments. They recommend thathead-injured patients with a GCS score of lessthan 15 sht)uld have balf-hourly observationsrecorded until the maximum score is reached,while patients with a GCS score of 15 should berecorded half-hourly for two hours, one-hourlyfor four hours then two-bourly thereafter.Although this a useful guide, within clinicalareas the patient's neurological conditionusually dictates the frequency of tbeobservations, and any adverse change in thepatient's condition is an indication to increasethefrequency of observations. Quality ofobservations is at least as important as quantity.

Discontinuation of neurologicalobservations relies on individual clinicaljudgement, but it is reasonable to stop them ifthe patient has been consistently stable for acouple of days provided that the initialpathology has been rectified (NICE 2003).

Discussion

Addison and Crawford (1999] reported thatthe GCS assessment tool is oftenmisunderstood and misused, and there is littleevidence to suggest that this situation haschanged or improved recently. Research hasshown that when the GCS observation chart isused by general nurses, as opposed to specialist'neuroscience' nurses, it can take up to twohours longer to detect a deterioration in thepatient's neurological status (Crewe and Lye1990, Eieidmgand Rowley 1990). This isprobably because experienced neurosciencenurses are more practised at identifying thealmost imperceptible signs of altered levels ofconsciousness and drowsiness, as well as themore subtle behaviour changes that suchpatients may exhibit.

Soon after the introduction ofthe GCS,Jennett and Teasdale (1977) acknowledgedthat 'the validity of the assumption that each ofthe three parts of the scale should countequally, and that each step should differ equallyfrom the next to it, has still to be tested'. Thisstatement still holds true, despite research thatexamined the inter-rater reliability of the chartandconcluded that the tool may be used withconfidence to evaluate neurological patients(Lyons andjuarez 1995, Teasdale era/1979).

However, to state that a patient has a GCSscore of 5 or 8 or 11 tells us very little about thepatient's exact neurological status, and it isimportant not to take any aspect ofneurological assessment in Isolation (Watson etal 1992). When communicating the GCS scoreit is good practice to state it in terms of theindividual components, for example, E3, V2,M4 - indicating that the patient opens his or

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her eyes to speech, offers incomprehensibleverbal responses and flexes to a painfulstimulus.

'The GCS is a tool that, with education, issimple to use, highlights changes in the patient'scondition and allows nurses and doctorsworking in different hospitals to communicatethe patient's state of consciousness in a clearand objective way' (Addison and Crawford1999). Lowry (1999) was critical of thestructureof the chart; however, it is not thechart design or its underlying objectives that areflawed, but the way it is implemented in theclinical areas.

Conclusion

Addison and Crawford (1999] recommend thatall new staff are taught how to apply the GCStool in clinical practice. This should be extended

to all healthcare practitioners involved in thecare and management of potentially vulnerableand unconscious patients, and should apply toall neurological observations. Although manyspecialist benchmarking groups have writtenbest practice guidelines, further audits andresearch are needed to establish why errors arestill being made when performing neurologicalobservations.

To maintain the ethos of benchmarking, it isessential that we share our knowledge and skillswith colleagues m other areas to ensure thatneurological observations are performedaccurately, safely and consistently NS

Now that you have completed thearticle you might tike to write apractice profile. Guidelines to help you areon page 67

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