Secondary brain ischaemia (SBI) usually develops after aneurysmal subarachnoid haemorrhage (SAH) and severe traumatic brain injury (TBI). The current management strategies are based on intracranial pressure-targeted therapy (ICP-targeted) with cerebral microdialysis monitoring (modified Lund concept) or cerebral perfusion pressure-targeted therapy (CPP-targeted). We present a randomised controlled study to compare the two management strategies.