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EVALUATION OF THE UNCONSCIOUS CHILD. COMA. COMA is a state of complete: absence of awareness of self absence of purposeful responsiveness to the environment absence of cognitive and mental functions. COMA.
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EVALUATION OF THE UNCONSCIOUS CHILD DR. TA OGUNLESI (FWACP)
COMA • COMA is a state of complete: • absence of awareness of self • absence of purposeful responsiveness to the environment • absence of cognitive and mental functions. DR. TA OGUNLESI (FWACP)
COMA • Consciousness depends on the interaction between the cerebral hemispheres and the Reticular Activating System (RAS), the arousal mechanism of the upper brain stem. • Altered sensorium results from either widespread cerebral disorder or destruction of the upper brainstem. DR. TA OGUNLESI (FWACP)
GRADES OF ALTERED SENSORIUM • Drowsiness-patient is easily arousable. • Delirium-patient has extreme motor agitation and severe disorientation with delusions and hallucination. • Stupor-patient arousable only on vigorous external stimulation. • Semi-consciousness-patient responds to vigorous stimulation with reflex limb movement but without mental response. • Coma-patient is completely unarousable. DR. TA OGUNLESI (FWACP)
AETIOLOGY OF COMA IN CHILDREN • Metabolic –more common in children (>50% of cases); gradual onset with slow progression and diffuse pattern of signs. The precise cause of coma is unclear but it is often due to cerebral oedema. • Structural- less common; sudden onset with rapid progression and focal distribution of signs. • Supratentorial • Infratentorial • Transtentorial The cause of coma is usually due to compression or direct destruction of the cerebrum and herniation of the brainstem. DR. TA OGUNLESI (FWACP)
ACUTE BRAIN INJURY • Alteration in sensorium usually results from acute brain injury which may be: • Traumatic (intracranial bleeding) • Infectious (meningitis/ encephalitis) • Metabolic (glucose, electrolyte derangements) • Hypoxic (status epilepticus, cardiac arrest) DR. TA OGUNLESI (FWACP)
ACUTE BRAIN INJURY • These injuries secondarily cause cerebral oedema via alteration in the cerebral blood flow and perfusion. • ↑Cerebral perfusion results in CEREBRAL OEDEMA formation which further worsens the elevated intracranial pressure. • Major risk of raised intracranial pressure is herniation of the brainstem into the foramen magnum (a.k.a coning) DR. TA OGUNLESI (FWACP)
WHEN TO SUSPECT CEREBRAL OEDEMA • Gradual decline in consciousness • Unequal or fixed pupillary dilatation • Cushing’s Triad • Conjugate or disconjugate eye deviation • Development of decorticate or decerebrate rigidity • Note that the classical features of headache, effortless vomiting and blurred vision are only found in chronically elevated intracranial pressure. DR. TA OGUNLESI (FWACP)
AETIOLOGY • Structural • Cerebral contusions or lacerations with hematomas, • Cerebral abscesses • Subdural effusions and empyema • Cerebrovascular diseases (AV malformations, aneurysms) • Cerebral tumours • Cerebral parasitic cysts (Cysticercosis; hydatidosis) DR. TA OGUNLESI (FWACP)
Metabolic & Diffuse Hypoglycaemia Hyperbilirubinaemia Hypothermia Severe anaemia Infections (Cerebral malaria, meningitis, encephalitis, cortical thrombophlebitis) Hypoxic-ischaemic encephalopathy Epilepsy DKA Alcohol intoxication Hypertensive encephalopathy Hepatic encephalopathy Uraemic encephalopathy Addison disease Thyroid crisis Reye syndrome Amino-aciduria Organic aciduria AETIOLOGY DR. TA OGUNLESI (FWACP)
ASSESSMENT OF SENSORIUM • GLASGOW COMA SCALE/ SCORE • Applicable for children aged 4- 15 years • Maximum score = 15 • Minimum score = 3 • Coma = score <8 DR. TA OGUNLESI (FWACP)
ASSESSMENT OF SENSORIUM • MODIFIED GLASGOW COMA SCALE/ SCORE • Applicable for children aged <4 years • Maximum score = 15 • Minimum score = 3 • Coma = score <8 DR. TA OGUNLESI (FWACP)
ASSESSMENT OF SENSORIUM • BLANTYRE COMA SCALE/ SCORE • Applicable for children who have not learnt to speak. • Maximum score = 5 • Minimum score = 0 • Coma = score <2 DR. TA OGUNLESI (FWACP)
ASSESSMENT OF AN UNCONSCIOUS CHILD OBJECTIVE-To minimise further brain injury • Ensure adequate resuscitation • Clear the airways • Secure the airways by positioning in the left lateral. Insertion of an oro-pharyngeal airway may be necessary. • Maintain circulation with the appropriate Intravenous Fluid (Normal Saline if shocked; Dopamine or dobutamine infusion may be necessary if in shock; dextrose-containing IVF in other cases). DR. TA OGUNLESI (FWACP)
ASSESSMENT OF AN UNCONSCIOUS CHILD • Check RBS even if with Dextrostix & correct hypoglycaemia if present. 2. Brief history focused on: • Mode of onset of impaired sensorium • Course and duration of illness • Drug use history DR. TA OGUNLESI (FWACP)
ASSESSMENT OF AN UNCONSCIOUS CHILD 3. Thorough physical examination focused on: • Assessment of sensorium using the Glasgow, Modified Glasgow or Blantyre scales. • Check for tense anterior fontanelle in infants; evidences of head injury: skull fracture or scalp lacerations. • Check the pupils for size, equality and reaction to light. DR. TA OGUNLESI (FWACP)
ASSESSMENT OF AN UNCONSCIOUS CHILD d. Check for meningeal irritation with Kernig or Brudzinski signs. e. Examine the fundus for papilloedema (raised intra-cranial pressure) or choroidal tubercules (miliary TB). f. Observe conjugate eye movements. Note the resting position of the eyes first and then briskly turn the head to either side to elicit the DOLL’S EYE MOVEMENT (OCULOCEPHALIC REFLEX). DR. TA OGUNLESI (FWACP)
ASSESSMENT OF AN UNCONSCIOUS CHILD • Deviation of the eyes to the contralateral side suggests cortical or brain stem depression. This manoeuvre brings the eyes beyond the midline in cortical diseases but not in brainstem diseases. • Downward deviation of the eyes (setting sun appearance) suggest mid-brain compression DR. TA OGUNLESI (FWACP)
ASSESSMENT OF AN UNCONSCIOUS CHILD • Assess the pulses and BP. Bradycardia and hypertension and apnoea (CUSHING’S TRIAD) suggest raised intra-cranial pressure but the triad is NOT always present. DR. TA OGUNLESI (FWACP)
ASSESSMENT OF AN UNCONSCIOUS CHILD • Examine the cranial nerves (particularly squint for 3rd, 4th and 6th; corneal reflex for 5th; facial deviation for 7th) • Examine the nose and ears for CSF drainage in cases of skull basal fracture. • Examine the mouth: breath of alcohol, ketones, native herbs. Tongue laceration may indicate recent seizure. DR. TA OGUNLESI (FWACP)
ASSESSMENT OF AN UNCONSCIOUS CHILD • Observe the posture (decorticate or decerebrate) • Examine the motor (bulk, tone, reflexes, power) and sensory functions (pain and superficial reflexes in particular). • Examine the skin and mucous membranes for palor, jaundice and uraemic frosts. DR. TA OGUNLESI (FWACP)
RELEVANT LABORATORY INVESTIGATIONS • CT Scan/ MRI • Cerebral angiography/ Ventriculography • Electroencephalography (EEG) • Skull X-Ray • CBC including ESR • RBS • Serum Electrolytes & Urea • LFT • Lumbar Tap if meningitis is suspected and evidences of raised intracranial pressure are absent. DR. TA OGUNLESI (FWACP)
CONTRAINDICATIONS TO LUMBAR TAP IN A COMATOSE PATIENT • Cardiopulmonary instability • Advanced brainstem dysfunction (eg. decerebrate posturing) • Gross skin sepsis over the spine • Evidence of Space-Occupying Lesion DR. TA OGUNLESI (FWACP)
MANAGEMENT • Treatment of specific aetiology • Supportive management • Left-lateral positioning to prevent aspiration • Frequent oro-pharyngeal suctioning to prevent aspiration DR. TA OGUNLESI (FWACP)
Endotracheal intubation if apnoea occurs • Maintenance of caloric and fluid intake via IVF, hyperalimentation or nasogastric intubation • Urethral catheterisation • Treatment of pressure areas to prevent decubitus ulcers DR. TA OGUNLESI (FWACP)
MANAGEMENT 3. Treatment of cerebral oedema • Elevation of the head to 15 to 300 optimises the cerebral perfusion pressure • Control of fever prevents ↑ cerebral blood flow, cerebral perfusion and oedema. Antipyretics and muscular paralysis to prevent shivering may be helpful. DR. TA OGUNLESI (FWACP)
Assisted Ventilation: To achieve hypocapnoea which causes cerebral vasoconstriction and reduces cerebral swelling. • Deliberate under-hydration (2/3 to ¾ of normal fluid requirement) has not been found to improve outcome because it further reduces resultant CPP. DR. TA OGUNLESI (FWACP)
MANAGEMENT Control of seizures with anticonvulsants (seizures increases the metabolism of brain tissue and ↑ the risk of oedema). Mannitol is used when herniation is imminent. Given as 0.5-1g/kg by rapid IV infusion over 20 minutes. Causes osmotic diuresis. May be repeated in 4 hours. Corticosteroids (Dexamethazone 0.2mg/kg/day iv or im) are useful only in vasogenic cerebral oedema (found in cases of CNS infections, abscesses and tumours). DR. TA OGUNLESI (FWACP)