Cerebral perfusion pressure and brain ischaemia: can one size fit all?

Current recommendations regarding the management of patients after traumatic brain injury include reduction in brain tissue pressure (i.e. intracranial pressure) and maintenance of an adequate arterial pressure; these measures combined should result in cerebral perfusion pressure sufficient to achieve adequate oxygen delivery. After almost 20 years of observational studies comparing cerebral perfusion pressure and indices of cerebral oxygenation, it is apparent that there is no single value for cerebral perfusion pressure that, if achieved, will provide adequate cerebral oxygen delivery in all patients. Traumatic brain injury remains a common problem, and this should encourage researchers and clinicians to design better and adequately powered trials of monitors and associated interventions.