Targeted treatment of severe head injury

Abstract

It has been increasingly appreciated in recent times that head
injury is not a homogeneous concept and is poorly classified for the
purposes of treatment.1 The separation of patients into 3 categories
of severity (mild, moderate and severe) remains a blunt measure
used to guide therapy in individual patients. Patients with severe
traumatic brain injury (TBI), i.e. a Glasgow Coma Score (GCS) ≤8,
may have different pathologies, including an extradural haematoma,
subdural haematoma, cerebral ischaemia, cerebral hyperaemia,
vasospasm, diffuse axonal injury, and/or focal haemorrhagic
contusions. Moreover, autoregulation of the links between cerebral
blood flow (CBF) and blood pressure, carbon dioxide tension,
and cerebral metabolic requirements may be variably impaired in
individuals – all of which have major implications for treatment.
Yet traditional management tends to treat all individuals similarly.
For example, intracranial pressure (ICP) is usually treated in a
standardised stepwise approach. Yet in individual patients, elevated
ICP may be associated with cerebral hyperaemia or cerebral
ischaemia, subclinical seizures, or impaired autoregulation (where
it is the elevated blood pressure that is the underlying problem). To
target these appropriately would require accurate diagnosis and a
different approach to management.