How to manage blood pressure after brain injury?

Manipulation of blood pressure (BP) is a mainstay of therapy in patients with acute brain injury (ABI). In the early emergent phase (first hours from injury), depending on intracranial pathology, BP manipulation aims to: 1) limit the progression of parenchymal hematomas or hemorrhagic transformation (in patients with ischemic/hemorrhagic stroke and aneurysmal subarachnoid hemorrhage [SAH]), and 2) attenuate hypoperfusion and secondary cerebral ischemic insults (in patients with traumatic brain injury [TBI]). During the intensive care unit (ICU) phase, BP management is primarily focused at identifying the so-called "optimal" BP/cerebral perfusion pressure (CPP), i.e. the threshold of mean arterial pressure (MAP)/CPP to prevent secondary cerebral ischemia. BP augmentation is also an essential component of the medical management of delayed cerebral ischemia following SAH. Increasing clinical data support the use of surrogate monitoring modalities of cerebral perfusion (including trans-cranial Doppler and brain tissue oximetry) to indentify BP/CPP targets in ABI patients. We reviewed herein the actual evidence regarding BP control in the early phase after ABI and recent clinical investigations using multimodal monitoring to optimize CPP and BP in severe ABI patients. The main purpose of this review is to provide a pragmatic approach of BP management, taking into account the timing of injury and differences in brain pathologies.