altered consciousness

• 1.

2. Altered consciousness and coma By Dr. Osman Sadig Bukhari 3.

• The reticular activating substanceinfluence the state of arousal.Our state of consciousness isthe product of complexinteractions between parts ofreticular formation itself, cortexand brainstem and sensory

• stimuli reaching them.

4.

• Coma:-is a state in which za pt isunrousable and unresponsive to external stimuli

• -Glasgow Coma Scale(GCS) is

• used for grading coma.

• - It hasmany causeswhich should

• be investigated and treated

• -Diagnostic workup of comatosed

• pt. must proceed concomitantly

• with management.

5.

• Glasgow Coma Scale (GCS)

• Eye opening(E):

• Spontaneous4

• To speech3

• To pain2

• No response1

• Motor response(M)

• Obeys6

• localizes5

• Withdraws4

• flexion3

• Extension2

• No response1

6.

• Verbal response(V)

• Oriented5

• Confused conversation4

• Inappropriate words3

• Incomprehensive sounds2

• No response1

• GCS= E+M+V

• - 50% of pts wz score of 4 or less will die

• - Death is rare wz score of 13 or more

• - GCS should be assessed every -2 hrs.

7.

• Mechanism of coma:

• 1-diffuse brain dysfnas in metabolic and

• toxic disorders which depress brain fn.

• 2-lesions within za brainstemwhich

• damage za reticular activating system

• 3-pressure effect on za brainstemfrom

• mass lesions inhibiting za reticular

• activating system

8.

• Causes of coma:

• 1-Head injury( extradural hage, SDH and

• cerebral contusion)

• 2-Infections : - cerebral malaria

• - meningitis

• - encephalitis, African trypan

• 3-Endocrine :- diabetes M:- hypoglycemia

• - DKA

• - hyper osmolar

• - hypothyroidism

• - hypopituitarism

• - hypoadrenalism.

9.

• 4-Metabolic:-hypo & hyper natraemia

• - hypo & hyper calcemia.

• - metabolic acidosis

• - renal, hepatic & resp failure

• - porphyria

• - thiamine deficiency.

• 5-Toxins & drug overdose:-

• - alcohol

• - CO poisoning

• - barbiturates, etc.

• 6-Epilepsy

• 7-Cerebrovascular diseases .

10.

• 8-Heat stroke, hypothermia, hypoxia

• 9-Intracranial mass lesions

• 10-Psychogenic

11.

• Immediate assessment and

• Emergency measures:

• 1-Position:pt on one side wz za neck

• partly extended.

• 2- EnsureA irway , B reathing& C irculation

• 5-Dextrose 50%

• 6-Head injury : observe & investigate

• 7-Spinal injury : immobilize.

• 8-Take blood forsugar, electrolytes, Ca

• renal & hepatic fn, blood gases, toxicol

• 9-Document degree of coma using GCS

12.

• Further steps to identify za cause :

• 1-Historytaken from a relative, eye wittn

• or policeman

• - Look foridentification card, wrist band

• or necklacee.g. diabetics, epileptics

• and pts on C/S.

• -Onsetof coma &time courseof

• subsequent events.

• - Historyhead injury& subsequent

• course.

• - History offever .

13.

• -PMH : DM, epilepsy, renal, hepatic and

• endocrine dis, psychiatric illness

• -Social & drug history : insulin, oral hypo

• 2-General medical examin comatosed pt:

• - Evidence ofsocial decline

• - Evidence oftrauma

• -Temperature

• - S kin & mucous membranese.g. pallor

• jaundice, cyanosis, purpura, injection

• marks, sweats, texture (dry & coarse

• in hypothyr), rash, pigmentation.

14.

• - B reath : for alcohol, acetone, hepatic

• and uraemic fetor.

• - R espiration :-Kussmaulbreathing.

• -Chyne Stokesbreathing

• -Central neurogenic

• hypervent in pontine lesi

• (deep & rapid breathing)

• -ataxic resp : shallow, halt

• irregular resp. wz medull

• resp centre damage &usually preceeds death

15.

• - G eneral systemic exam .

• 3-Neurological exam in comatosed pt :

• a- H ead, neck & spine

• b- Pupil size & reaction to light

• - unilateral light fixed dilated pupil=coning of za uncus (compress of 3)

• - bilateral light fixed dilated

• pupil= brain stem death, deep

• coma from barbit, hypoth.

• - unilat. small pupil + ptosis= Horners

• - bilateral pin point light fixed pupils

• = pontine hage, opiate poisoning

16.

• -bilateral mid point reactive pupils=metab

• and CNS depressants except opiat

• c-Ocular movements

• - sustained conjugate lateral deviation

• occurs towards za side of a destructive

• frontal lesion

• - dysconjugate deviation= structuralbrainstem lesion

• - oculocephalic response (dolls head reflx

• is lost in deep coma & BD

• - caloric or vestibulo-ocular reflex is lost

• in coma due toBD.

17.

• - skew deviation= brain stem or cerebell

• lesions.

• - ocular bobbing= pontine or cerebell les

• d-Fundi:for papilloedema & haemorrhage

• e-Lateralizing signs

• - facial asymmetry

• - tone

• - asymmetric response to painful stimul

• - asymmetry of planter response

• - asymmetry of reflexes

• - asymmetry of decorticate or

• decerebrate posturing.

18.

• Investigation of comatosed pt

• - BFM- Urine ex.- CBC

• - blood biochemstry

• - Endocrine- Toxicology

• - ECG & CXR

• - immaging- EEG- ABG

• - CSF- blood culture

19.

• Management of comatosed pt

• 1- careful nursing

• 2- attention toA irway,B reathing &C ircul

• 3- IV canulae & fluids

• 4- NG tube & feeding (calories)

• 5- catheterization

• 6- frequent monitoring & charting of

• vital signs.

• 7- skin care & oral hygiene

• 8- care of za eye

• 9-treat zaCAUSE.

20.

• Brain death (BD)

• - Death= no spontaneous resp or heart

• beat.

• - BD should be considered in deeply

• comatosed ventilated pts in whom

• curable causes have been excluded.

• - Criteria are laid down before pt put off

• ventilator & organs taken for donation.

21.

• Pre conditions for diagnosis of BD

• 1- Patientdeeply comatosed

• 2- Patientinadequately breathing or has

• ceased breathing & put on mechanical

• ventilatori.e. NO spont breathing if ptput off ventilator long enough (CO2tension 6.7 kp= 50mm Hg)

• 3-NO drugis responsible for comaincluding N/M blocking agents,sedatives or anticonvulsants.

• 4-NO hypothermia(rectal temp >35)

22.

• 5-NO metabolic or endocrinecauseofcoma. No profound abn of plasma Eand acid- base balance or bloodglucose level. 6- Evidence ofirremediable structural brain damage e.g. head injury intracranial hage.

• 7-The diag should be confirmedby 2

• experienced Drs: two consultants or

• at least one consultant & senior registr

• and tests of BD repeated in 24 hrs

• before final diag.

• *Diag of BD: stop vent & other life suppor

• measures. Organ taken for trnaspl .

23.

• Confirmatory tests for BD

• All brain stem reflexes are absent .

• Tests : NOTperformed in the presence of seizure or abnormal