Raised ICP is monitored with a ventricular catheter or surface pressure recording device; treatment is instituted when the mean ICP exceeds 30 mm Hg. This is a specialist area and local neurosurgical advice should be sought.
Currently available medical treatments for raised intracranial pressure include hyperosmolar therapy, sedation and paralysis, hyperventilation, barbiturates, hypothermia, steroids and surgical intervention.
Management approach depends upon the source of the raised pressure:
- space occupying lesion - remove lesion surgically
- increased CSF - burr hole with an external drain or shunt
- cerebral oedema - mannitol, a sugar alcohol acts as an osmotic diuretic, causing sustained hyperosmolarity by dehydration, has become the most widely used hyperosmolar solution to treat elevated intracranial pressure
- osmotic diuretics such as mannitol
- associated with hypovolaemia and the induction of a hyperosmotic state - danger of reduced cerebral perfusion;
- steroids are good for cerebral oedema secondary to tumours and abscesses, poor for trauma. Other measures include the use of barbiturates and hyperventilation
- hyperosmolar therapy is the cornerstone of pharmaceutical treatment for intracranial hypertension
- hypertonic saline has emerged as an alternative hyperosmolar agent after several trials reported its relative superiority, especially for refractory intracranial pressure
- evidence that intravenous bolus administration of hypertonic saline resulted in a sustained reduction of intracranial pressure on patients with traumatic cerebral oedema, even when elevated intracranial pressure is resistant to other intracranial pressure-lowering agents including mannitol
- concentration and volume of hypertonic saline for clinical use range from 2% to 23.4% in concentration and 10 to 30 mL/kg in volume
- based on limited data, there is weak evidence to suggest that hypertonic saline is no better than mannitol in efficacy and safety in the long-term management of acute traumatic brain injury (1)