Biomarkers and neuroimaging of brain injury after cardiac arrest.

Unfortunately, it remains a difficult task to predict with certainty which patients will have a poor neurological outcome following cardiac arrest. Finding a quantitative prognostic model of outcome has become the objective of many intensivists to assist grieving families in making early difficult decisions regarding withdrawal of life support. An ideal prognostic test should be readily available, easily reproducible, and associated with a high degree of specificity for poor outcome. The goal is not to define which patients may recover, but rather which patients have no likelihood of meaningful neurological recovery at all to justify early withdrawal of support. The literature and the role of biochemical markers in the blood and in the cerebrospinal fluid will be evaluated as prognosticators following cardiac arrest. Radiological indicators of anoxic cerebral damage are reviewed. Each serum or radiological marker has its pros and cons. To accurately prognosticate following cardiac arrest, a multimodal scale or algorithm that incorporates serum markers, radiological markers, and the neurological exam is clearly needed. As these techniques are being evaluated more closely and as imaging modalities increase in sensitivity and portability, physicians will continue to assist families by providing some guidance as to which patients have no chance of meaningful recovery.