altered consciousness

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  • 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

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