What Works for Brain Protection?

Perioperative neurologic adverse events range from frank stroke to subtle cognitive dysfunction. A substantial amount of effort has been made to improve outcomes, especially in patients undergoing cardiac or vascular surgery who are considered to be higher risk for worse neurologic outcomes. Despite promising data from preclinical research, there have been no formal guidelines because of a lack of strong clinical evidence. Neuroprotective strategies are classified into two main concepts: passive, which refers to avoidance of deleterious factors; and active, which refers to the application of beneficial interventions. In this chapter, we will discuss the preclinical and clinical evidence of five categories of neuroprotection strategies: (1) physiology, or avoidance of hyperthermia, hyperglycemia, cerebral hypoxia, and hypoperfusion; (2) anesthetics, or the use of anesthetics that are potentially neuroprotective; (3) pharmacology, or the use of potentially neuroprotective agents that can block the pathways of neuronal cell death; (4) preconditioning/postconditioning, or the use of physiologic or pharmacologic alterations that could mimic ischemic preconditioning/postconditioning; and (5) monitoring, or the use of epiaortic ultrasound to alter the surgical technique and near-infrared reflectance spectroscopy for the assessment of bifrontal regional cerebral oxygen saturation.