Maintaining cerebral perfusion pressure is a worthy clinical goal

Cerebral perfusion pressure (CPP) is one aspect of an all-encompassing approach in the management of traumatic brain injury (TBI). The clinical use of CPP is based on theoretical considerations that optimal cerebral blood flow is necessary to meet the metabolic needs of the injured brain. The goal is to preserve the ischemic penumbra and avoid secondary insults. Unfortunately, lack of objective measures of local tissue response and randomized controlled clinical trials prevents confirmation that these goals are being met when actively treating CPP. The present recommended threshold CPP for intervention in the literature is 70 mmHg. However, this specific CPP level is being challenged. There is increasing evidence that this and higher CPP thresholds are not necessary and that a lower CPP may be as clinically effective. There are clinical prospective, but not randomized, human trials showing that CPP 60 to 70 mmHg may be reasonable. Recently, the Brain Trauma Foundation updated their Web-based recommendation of a lower CPP goal of 60 mmHg. However, the lack of definitive data, such as from a randomized prospective intention-to-treat clinical trials, leaves this goal open to controversy. Therefore, for a variety of reasons, the physician may be most prudent to use the published CPP guideline of 70 mmHg until a consensus statement is published advocating a different value.