Raised intracranial pressure (ICP)
Overview
Raised intracranial pressure is a common, potentially life‑threatening presentation in the emergency department. Early recognition, physiological stabilisation and timely escalation to neurosurgery/critical care reduce secondary brain injury.
The ED clinician must identify red flags from the history and examination, recognise imaging features that mandate urgent discussion, start immediate stabilising measures and use temporising therapies while arranging definitive management.
Pathophysiology
The Monro-Kellie doctrine describes the fixed intracranial volume: increases in brain tissue, cerebrospinal fluid (CSF) or blood that exceed compensatory mechanisms raise ICP.
Common mechanisms include space‑occupying lesions (tumour, haematoma), vasogenic or cytotoxic oedema, raised intracranial blood volume (eg, venous sinus thrombosis, hypercapnia), hydrocephalus and intracranial infection.
Rising ICP reduces cerebral perfusion pressure (CPP = MAP - ICP) and, if severe, may cause transtentorial or tonsillar herniation.
History - key red flags
Headache is common but nonspecific. Elicit features that suggest raised ICP or a secondary cause (adapted from SNOOP4/RCEM guidance):
- Positional worsening: worse on lying flat, on waking, or on bending/stooping.
- Valsalva/exertional provocation: worse with coughing, straining, sneezing or exertion.
- New, progressive or changed headache, especially if age
> 50.