In coma, immediate aims are to maintain homoeostasis and treat the treatable. If stable, a more detailed neurological examination will help:
Lateralization suggests a localised rather than a generalised lesion but this is often a false indicator in childhood. The child will almost certainly need a CT scan.
Unless meningitis can be excluded by clear identification of another cause for coma, it should be assumed present. Aciclovir should also be considered as herpes encephalitis has a worse prognosis when treatment is seriously delayed. Senior advice should be sought. Lumbar puncture should not be performed in coma. It can be delayed until the child's condition allows, to confirm or refute the diagnosis.
A vague and inconsistent history and/or suspicious bruising in an infant is suggestive of intracerebral bleeding from child abuse. The presence of retinal haemorrhage is strong presumptive evidence (see head injury management).
Sudden onset with/without preceding headache points to stroke (rare in childhood).
Significant hypertension points to hypertensive encephalopathy.
Bacterial meningitis is difficult to diagnose in its early stages in the under 3 yrs. Classic signs are often absent. A bulging fontanelle is a sign of advanced meningitis in an infant, but even this serious and late sign will be masked if the baby is dehydrated. Signs of possible meningitis include:
Older children are more likely to have classic signs of headache, vomiting, pyrexia, neck stiffness, photophobia. An abnormal breathing pattern or decorticate/decerebrate posture may suggest raised intracranial pressure.
Any child in whom meningitis is suspected should now receive IV cefotaxime or other suitable antibiotic. There is evidence that dexamethasone (0.15 mg/kg IV) given before or at the same time as the initial antibiotic improves outcome in cases of Haemophilus influenzae. There is no evidence of benefit in meningitis caused by other organisms.
There are only 3 absolute signs of raised intracranial pressure, namely papilloedema, bulging fontanelle and absence of venous pulsation in retinal vessels. All are often absent in acutely raised ICP. In a previously well unconscious child (GCS<9) who is not postictal, suggestive signs are:
It is now usual practice to treat a child with obvious meningitis with antibiotics immediately and perform a lumbar puncture if necessary some days later when clearly no longer suffering from raised ICP. Relative contraindications are:
After stabilization of ABC, specific antidote is naloxone. An initial bolus dose of 10 mcg/kg is used but some children need doses as high as 100 mcg/kg up to a maximum of 2 mg. Naloxone has a short halflife, relapse occurring after 20 minutes. Further boluses or an infusion of 10-20 mcg/kg/min may be needed.
It is important to normalise CO2 before naloxone is given as adverse events eg ventricular arrhythmias, pulmonary oedema or seizures may otherwise occur. This is because the opioid system and adrenergic system are interrelated, so if ventilation is not given to support the frequent hypoventilation first the sudden rise in epinephrine concentration can cause arrhythmias.
After the child has been stabilised and treatable conditions have been treated, some children will remain a puzzle. Any suggestion of lateralisation or intracranial bleeding should have na urgent CT scan. Children who remain very ill or undiagnosed will require referral to a paediatric neurologist and may need transfer to a paediatric intensive care unti. Patients may need paralysis, intubation and ventilation for safe transfer: in such patients neurological assessment cannot be continued and there should therefore be clear documentation of neurological signs before paralysis is commenced.