The management of traumatic brain injury focuses on the prevention of second insults, which most often occur because of a supply/demand mismatch of the cerebral metabolism. The healthy brain has mechanisms of autoregulation to match the cerebral blood flow to the cerebral metabolic demand. After trauma, these mechanisms are disrupted, leaving the patient susceptible to episodes of hypotension, hypoxemia, and elevated intracranial pressure. Understanding the normal and pathologic states of the cerebral blood flow is critical for understanding the treatment choices for a patient with traumatic brain injury. In this chapter, we discuss the underlying physiologic principles that govern our approach to the treatment of traumatic brain injury.
This review contains 3 figures, 1 table and 12 references
Key Words: cerebral autoregulation, cerebral blood flow, cerebral metabolic rate, intracranial pressure, ischemia, reactivity, vasoconstriction, vasodilation, viscosity
165 CEREBRAL BLOOD FLOW AUTOREGULATION WITH ELEVATED INTRACRANIAL PRESSURE DURING NORMOXIA AND HYPOXIA