“Did you do a CT head to confirm there is no raised intracranial pressure?”, says the 1950s dressed radiologist passing by as you gather the lumbar puncture equipment. You say “no”. You wonder whether now is a good time to point out the latest NICE guidelines that state: “Do not use cranial computed tomography (CT) to decide whether it is safe to perform a lumbar puncture. CT is unreliable for identifying raised intracranial pressure.” (originally for the context for meningitis, but it is true in general that CT does not rule out raised ICP)
You were smart enough to check for raised intracranial pressure (eg raised ICP headache, unexplained focal neurology, unexplained seizures, reduced GCS, papilloedema) before LP.
However, the NHS is sometimes a risk adverse environment. The policy here may not be super up to date with the cutting edge of what may be safely omitted. The patient goes for a CT, ostensibly to rule out “mass effect/raised ICP”.
The results from the CT head are back.
What do you expect to see on the CT head that would confirm your diagnosis of an extradural haematoma?