How do you decide between using an intracranial pressure monitor (bolt) versus an extraventricular drain (EVD) for intracranial pressure monitoring in cases of diffuse cerebral injury?

I think the decision about whether to place an external ventricular drain (EVD) or an intraparenchymal ICP monitor (IPM) rests on many factors, including:

1) Need for CSF drainage - if the patient has hydrocephalus or CSF drainage is anticipated to be useful in controlling ICP, then an EVD is prefera...