The Child with a Decreased Conscious level

Question 1

Name some of the disorders causing coma in children.

What is the most common cause?

Answer 1

VITAMIN CDE

95% = diffuse metabolic injury incl. cerebral hypoxia/ ischaemia

5% = structural brain lesions

• Vascular
  
  • hypoxic ischaemic brain injury (following resp/ circulatory collapse)
  • CVA (AV malformation or tumour)
• Inflammatory/ Infectious
  
  • meningitis / encephalitis
  • cerebral/ extracerebral abscesses
  • malaria
• Trauma
  
  • intracranial haemorrhage/ raised ICP
  • brain swelling e.g. hydrocephalus (incl. blocked intraventricular shunts)
• Metabolic/ Endocrine
  
  • electrolyte abnormality e.g. hyponatraemia/ hypernatraemia
  • renal/ hepatic failure
  • inherited metabolic disease
  • GLUCOSE - hypoglycaemia
  • CO2 - hypercapnia
  • TEMP - hypothermia
• Neoplastic - cerebral tumour
• Congenital
  
  • inherited metabolic disease
  • epilepsy (seizures)
• Drugs - intoxication

Question 2

What may focal neurological symptoms suggest in a child with reduced consciousness?

Answer 2

1. focal neurological lesion
2. metabolic disturbance
   
   • may produce diffuse / incomplete/ asymmetrical neurological signs

Question 3

Describe GCS and Children’s GCS.

Answer 3

not the DMV - the EMV!

(Eyes/ Motor/ Verbal – 4/6/5)

Lowest score in any is 1.

Bold = same in both

• GCS (4-15 YEARS) & [[Children’s (<4 yo)]]
  
  • E
    
    • 4 - eyes open spontaneously
    • 3 - to speech
    • 2 - to pain
    • 1 - no response
  • M
    
    • 6 - obeys commands [/spontaneous]
    • 5 - localises to PAIN [/withdraws to TOUCH]
    • 4 - withdraws from PAIN
    • 3 - Abnormal FLEXION to PAIN (decOrticate) – F before E,
    • 2 - abnormal EXTENSION to PAIN (decErebrate) Extension is DecErebrate
    • 1 - no response (to pain)
  • V
    
    • 5 - ORIENTED & converses [ABC - Alert/ Babbles/ Coos as normal)
    • 4 - DISORIENTED & converses [< usual words, irritable CRY)
    • 3 - Inaprropriate WORDS [CRIES only to pain]
    • 2 - Incomprehensible SOUNDS [MOANS to pain]
    • 1 - No response (to pain)

Question 4

Define CPP.

Answer 4

CPP = Cerebral Perfusion Pressure

CPP = MAP - ICP

Normal range = 40-60 mmHg

Question 5

Describe the pathophysiology of raised ICP in children.

Answer 5

NB Young children = cranial sutures not yet closed

• Brain tissue swelling/ Haematoma/ CSF blockage
• Intracranial volume expansion
• Young children/ SLOW –> HYDROCEPHALUS
• Older Children (fixed cranium) / FAST
• –> raised ICP
• –> compensating mechanism - reduces volume of CSF + venous blood in the cranium
• –> fails
• –> ICP continues to rise
• –> CPP falls
• –> CBF (cerebral blood flow falls)
• CBF should be > 50 ml/ 100g brain tissue/ min
• CBF < 20 ml/ 100 g brain tissue/ min
• –> brain ischaemia
• Brain tissue pushed against more rigid intracranial structures
  
  • –> Central syndrome
    
    • whole brain pressed down
    • cerebellar tonsils herniate through foramen magnum = CONING
    • –> TACHYCARDIA (initially)
    • –> BRADYCARDIA + high BP
    • –> IRREGULAR BREATHING
    • –> APNOEA
  • –> Uncal syndrome
    
    • large increase in volume in the supratentorial part of intracranial space
    • uncus (part of hiipocampal gyrus)
    • forced through tentorial opening
    • compressed against fixed free edge of tentorium
    • if unilateral pressure e.g. haematoma (subdural/ extradural) –> focal neuro signs e.g.
      
      • –> PUPIL = ipsilateral dilated (3rd nerve compression)
      • –> EYE MOVEMENT = cannot move laterally (external oculomotor palsy)
      • –> BODY = hemiplegia

Question 6

When does the anterior fontanelle close?

Answer 6

Between 9 - 18 months.

Question 7

Describe the signs of raised ICP.

What are the 3 absolute signs of raised ICP? (FAP)

Answer 7

FAP 5

In a previously well child,

GCS < 9 (Unconscious),

NOT post-ictal

1. Eyes & head
   
   • _*f*ontanelle bulging_
   • _retinal vessels - *a*bsence of venous pulsation_
   • _*p*apilloedema_
   • unilateral or B/L pupillary dilatation
   • abnormal oculocephalic reflexes (do not perform if ? C-spine injury
     
     • turn head L/ R –> eyes should move opposite to head direction VS. no/ random movement
     • flex neck –> upward gaze normal VS. no movement
2. Cushing’s triad (signs of impending brain herniation)
   
   • bradycardia (initially significant tachycardia)
   • HYPERtension
   • irregular breathing e.g. hyperventilation, Cheyne-Stokes breathing, apnoea
3. Posturing - in a previously well child – NB may need a painful stimulus to elicit
   
   • decorticate (flexed arms, extended legs)
   • decerebrate (extended arms & legs)
4. Seizures
5. Coma/ reduced conscious level

NB often absent in acutely raised ICP

Question 8

Describe the primary assessment and resuscitation of a child with decreased consciousness level.

Answer 8

ABCDEFG

• A
  
  • airway opening manoeuvres
  • adjuncts
  • I+V
  • NGT/ OGT
    
    • aspirate stomach contents
    • lavage if poisoning (when appropriate)
  • airway needs to be secured when
    
    • no gag reflex
    • P/ U on AVPU
  • support the airway
    
    • reduced consciousness may be due to hypoxia/ ischaemia (most common cause)
    • ensure adequate oxygenation to brain so any cerebral pathology does not get worse
• B
  
  • Signs
    
    • Kussmaul breathing? = acidosis
      
      • DKA
      • inborn error of metabolism
      • poisoning e.g. salicylates, ethylene glycol
  • High flow O2 non-rebreather
  • BVM if hypoventilating
    
    • rise in PCO2 can cause a rise in ICP
• C
  
  • Signs
    
    • raised BP + bradycardia = high ICP
    • hypertension may be the cause or result of coma
  • IV/ IO access
    
    • Glucose - gas + grey (lab) + green (1st hypoG)
    • baseline + plasma ammonia on ice (green) – metabolic coma
    • G+S/ cross-match
    • BCx + meningococcal/ streptococcal PCR
  • IVAB + antiviral + dex - ALWAYS unless there is a clear other cause for coma
    
    • cefotaxime/ ceftriaxone (sepsis/ meningitis/ encephalitis)
    • erythromycin (mycoplasma meningoencephalitis)
    • aciclovir (herpes meningoencephalitis)
      
      • **DO NOT DO LP - risk of coning and death**
      • **Normal fundi/CT does not exclude acutely raised ICP**
      • **early IVAB + antiviral is critical**
    • dexamethasone
      
      • suspected or confirmed bac. meningitis
      • > 3 months
      • reduces hearing loss + other longterm sequalae
      • 150 mcg/kg
      • max 10 mg
      • 4-12 hrs from ABx
  • Fluids
    
    • 20 ml / kg bolus OR 10 ml/ kg bolus (trauma/ cardiac)
    • maintenance fluids (unless raised ICP or SIADH)
    • monitor electrolytes, treat hyponatraemia
• D
  
  • Convulsions
    
    • may be subtle
  • Meningitic symptoms
    
    • Neck stiffness
    • Fontanelle full / tense
    • Rash - purpuric (meningococcal/ streptococcal) or NAI
    • Photophobia
    • Headache
    • Irritability
  • Signs of raised ICP - NB may also be a problem needing Rx in meningitis
    
    • I+V - aim PCO2 4.5 - 5.5
    • Nurse head in line + 20 degrees up (helps cerebral venous drainage)
    • Catheterise - bladder distension may aggravate raised ICP
    • Dx
      
      • 3% hypertonic saline 3 ml/kg
        
        • –> 0.1 - 1 ml/kg/hr
        • keep osmolality < 360
      • 20% Mannitol
        
        • 250-500 mg/kg (1.25 - 2.5 ml) over 15 mins
        • 2 hourly PRN if serum osmolality NOT > 325 mOsml/L
      • Dexamethasone
        
        • oedema around a SOL
        • 0.5 mg/kg 6 hrly
• E
  
  • Fever - try to avoid
    
    • sepsis
    • poisoning e.g. ecstacy, cocaine, aspirin
  • Hypothermia
    
    • poisoning e.g. barbiturates, ethanol
• Fluids
• GLUCOSE
  
  • hypoG = < 3 mmol /L (< 4 in diabetes)
  • if in doubt treat
  • 10% glucose - 2 ml/ kg
  • maintenance 5% or 10% in infants (to prevent rebound)
  • caution with insulin - hyperglycaemia may be stress induced

Question 9

What are the relative contraindications to LP?

Answer 9

• seizures - prolonged or focal
• focal neuro signs e.g. asymettrical limb movement/ reflexes, ocular palsies
• movement abnormal e.g. cycling movements of the limbs
• purpuric rash - widespread (BCx + start IVAB)
• thrombocytopaenia/ coagulation disorder
• Signs of ICP incl.
  
  • GCS < 13
  • pupillary dilatation
  • oculocephalic reflexes abnormal
  • posture abnormal - decerebrate / decorticate
  • cushing’s triad - hypertension (or alone), bradycardia, irregular breathing
  • papilloedema

Question 10

Describe the possible pupillary changes in coma and give examples of their causes.

Answer 10

SMALL - MIDSIZE - DILATED

REACTIVE VS. FIXED

UNILATERAL VS. B/L

• Small
  
  • Reactive
    
    • metabolic disorders
    • medullary lesion
  • Pinpoint
    
    • metabolic disorders
    • poisoning e.g. narcotics (morphone, heroin, codeine), organophosphates
• Midsize
  
  • Fixed
    
    • midbrain lesion
• Dilated
  
  • Fixed – ‘oh, S-H-HY-D!’
    
    • seizure - during & post
    • hypothermia
    • hypoxia - severe
    • drugs - anticholinergics + barbiturates (late sign)
  • Unilateral – ‘are you SE-R-TE-N?’
    
    • epileptic seizure
    • rapidly expanding ipsilateral lesion
    • tentorial herniation
    • 3rd nerve lesion

Question 11

Describe the secondary assessment of children with reduced consciousness level including history and examination (looking for key features).

Answer 11

• History
  
  • health & activity of the previous 24 hrs
  • any trauma?
  • PMH incl. pre-existing neuro disability, presence of shunts, epilepsy, metabolic disorder
  • Medications
  • ? poison ingestion
  • Allergies
  • Last meal
  • FHx - metabolic disorder?
  • Recent travel?
  • SHx
• Examination (top to bottom)
  
  • General – SOS (skin, odour, scalp)
    
    • Skin
      
      • rash
      • haemorrhage
      • trauma
      • neurocutaneous syndromes
    • Scalp
      
      • trauma?
    • Odour
      
      • alcohol
      • ketones (DKA, metabolic disorders)
  • Head & Neck
    
    • Eyes
      
      • pupils/ reactivity
      • fundoscopy
        
        • haemorrhage (trauma)
        • papilloedema (ICP raised)
      • eye movement
        
        • opthalmoplegia - lateral/ vertical deviation
    • Ears
      
      • Bloody/ clear discharge (base of skull #) = otorrhoea
      • otitis media / mastoiditis – may be w/ meningitis
    • Nose
      
      • Bloody/ clear discharge (base of skull #) = rhinorrhoea
    • Neck - meningitis / CVA –>
      
      • tenderness
      • rigidity
  • Neuro - any lateralisation in:
    
    • tone?
    • posture?
    • reflexes incl. plantar?
      
      • suggests localised lesion but may be a false indicator in children
      • consider CT/ MRI
  • Exposure - Abdomen:
    
    • enlarged liver + HypoG
      
      • metabolic disease

Question 12

Suggest the likeliest cause of reduced consciousness/ coma in the following examples:

1. coma that develops over several hours with irritability, fever, rash
2. opitate ingestion and or pinpoint pupils
3. minor illness with vomiting, hepatomegaly & hypoglycaemia
4. travel abroad
5. hypertension (significant) + coma
6. otherwise well child, sudden onset of coma within 1 hour
7. vague and inconsistent history, suspicious bruising, retinal haemorrhage
8. hyperglycaemia
9. very sudden onset coma +/- headache

Answer 12

1. meningitis/ encephalitis
2. opiate poisoning
3. metabolic encephalopathy
4. malaria
5. hypertensive encephalopathy
6. poisoning
7. NAI
8. diabetes
9. CVA

Question 13

What is the commonest cause of bacterial meningitis AFTER the neonatal period?

What is the mortality and incidence of serious sequelae?

Name some other common causes.

Answer 13

Neisseria meningitidis

5% mortality + 5% serious sequelae

Also:

• Streptococcus pneumoniae (after an URTI +/- otitis media, 30% sequelae)
• Hib (less common now with Hib vaccination)

Question 14

Describe the signs and symptoms which point to a diagnosis of bacterial meningitis in

• 4 years or older
• 3 years or younger

Answer 14

BACTERIAL MENINGITIS

• 4 years or older - classical signs:
  
  • fever
  • purpuric rash
  • headache
  • neck stiffness
  • photophobia
  • vomiting
  • +/-
    
    • convulsions
    • coma
• 3 years or younger
  
  • CLASSIC SIGNS OFTEN ABSENT
    
    • fever
    • purpuric rash
    • headache (can’t express)
    • neck stiffness (can’t express)
    • photophobia (can’t express)
    • vomiting –> POOR FEEDING
    • +/-
      
      • DROWSINESS (POOR EYE CONTACT)
      • convulsions
      • coma
  • bulging fontanelle
    
    • ADVANCED
    • may be absent if dehydration from sig. vomiting/ fever
  • Sx of raised ICP
  • high pitched cry/ irritability - not soothed by parent
  • cyanotic/ apnoeic attacks

Question 15

Describe the emergency management of opiate poisoning.

Answer 15

Usually from drinking green, liquid methadone.

Reduced GCS –> unstable airway + hypoventilation.

• ABCDE
  
  • NORMALISE PCO2 FIRST
    
    • opiod + adrenergic system are linked
    • naloxone + hypercapnia
      
      • –> sudden rise in adrenaline
      • : ventricular arrythmia
      • : asystole
      • : pulm. oedema
      • : seizures
• Naloxone
  
  • 10 mcg/ kg initially
  • max 2 mg total
  • short half life
    
    • may relapse after 20 mins
    • further boluses/ infusion = 10-20 mcg/kg/min

Question 16

What are the causes of metabolic coma?

Answer 16

1. Hypoglycaemia (common)
2. DKA (common)
3. Inborns errors of metabolism (rare)

Question 17

How do cases of inborn errors of metabolism present?

Answer 17

• encephalopathy (rapidly progressing)
• vomiting
• convulsions
• drowsiness –> coma
• hepatomegaly (fatty change)
• Ix
  
  • hypoglycaemia
  • abnormal LFTs
  • high ammonia (d/w PICU/ metabolic team)

Question 18

Which is the most dangerous malaria causing pathogen?

Answer 18

Plasmodium falciparum.

95% of malaria deaths.

Most severe complications.

Question 19

How is malaria transmitted?

Answer 19

1. Bite of an infected Anopheles mosquito
2. Blood transfusion
3. Needle stick
4. Transplacental

Question 20

What are the clinical features of severe malaria?

Answer 20

1. Reduced GCS NB encephalopathy/ rapid onset coma/ raised ICP (cerebral malaria)
2. Convulsions
3. Acidosis (metabolic)
4. Hypoglycaemia
5. Anaemia - severe, normocytic

Question 21

Describe the emergency Mx of cerebral malaria.

Answer 21

ABCDE

• C - severe P. falciparum
  
  • Artesunate
    
    • IV / IO
    • 2.4 mg/kg on admission –> @ 12 hrs –> @ 24 hrs –> OD
  • Quinine
    
    • alternative if artesunate not available
    • 20 mg/kg in 5% glucose
    • over 4 hrs
    • –> 10 mg/kg TDS
    • ECG monitoring
  • IVAB e.g. IV cefotaxime - risk of concomitant Gram -ve infection is high
  • Transfusion
    
    • Hb < 50
    • signs of heart failure
  • • CAUTIOUS FLUIDS
• G
  
  • Treat hypoG

Question 22

What are the indications for urgent CT in children with reduced consciousness level?

Answer 22

1. Unclear diagnosis
2. Lateralising signs
3. Raised ICP