Nursing 54A - Acute Disorders of Brain Function. Complete Study Guide.

Acute Disorders of Brain Function Question: The brain contributes ____% of body weight and uses ____% of the body’s O2 consumption? 2,20  It doesn’t weigh much  It does consume high amount of O2 and blood flow (re ...

Acute Disorders of Brain Function Question: The brain contributes ____% of body weight and uses ____% of the body’s O2 consumption? 2,20  It doesn’t weigh much  It does consume high amount of O2 and blood flow (relative metabolic rate is high) o Very significant in regards to ICP- amt of O2 consumption and therefore the amt of blood flow is high  Blood is a major component of ICP Question: Acute head injury produces high rates of both mortality and morbidity due to the damage produced by the primary brain injury. False Secondary injury  Primary injury- injury of the actual trauma (ex. necrosis from stroke)  Secondary injury- body’s response to that injury and the effects of that response  Really imp. in management. Can’t fix the primary injury (ex. dead tissue due to stroke), but can fix the Secondary injury issues (ex. inflammatory response to injury) typically. Mechanisms of Brain Injury  The ultimate outcome of the neurons is the ability to function as normalability to have ATP to function (goal: maintain O2 and perfusion of the cells) o We maintain ATP through O2 (maintain cell membrane (Na+ K+ pump and functioning of that cell)) o We maintain O2 through cell perfusion  Primary brain injury occurs as a direct result of the initial insult  Secondary injury refers to progressive damage resulting from the body’s physiologic response to the initial insult  A critical factor in determining the neuronal cell fate after injury is the degree of adenosine triphosphate (ATP) depletion Mechanisms of Brain Injury (Cont.) Ischemia and Hypoxia (la) Ischemia- lack of perfusion to the tissue (big factor in the secondary response)- causes lack of ATP / ATP depletion Hypoxia- lack of oxygenation to the tissue Hypoxemia- lack of O2 in the blood  Ischemia is a contributing factor either as the primary insult or as part of the secondary response to injury