Expansion
Reduce brain water, blood volume or cerebrospinal fluid, or increase the space
Expansion
Working through the Monro-Kellie compartments:
Brain (water)
- Mannitol or hypertonic saline, creating an osmotic gradient
- Steroids, but only for vasogenic oedema around tumours and abscesses, not for trauma or stroke where they are harmful
Blood
- Head up 30 degrees and neutral neck position, improving venous drainage
- Avoid raised intrathoracic pressure: treat coughing, straining and high PEEP
- Controlled hyperventilation to a PaCO2 of about 4.0 to 4.5 kPa, causing cerebral vasoconstriction. A short-term rescue only, since prolonged use risks ischaemia
- Sedation and analgesia to reduce cerebral metabolic rate; occasionally barbiturate coma
Cerebrospinal fluid
- External ventricular drain
The skull itself
- Decompressive craniectomy
Supportive: maintain cerebral perfusion pressure above about 60 mmHg, avoid hyponatraemia, hyperglycaemia, hyperthermia and seizures, all of which increase metabolic demand or worsen oedema.