NR-340 CRITICAL CARE Exam 3 study guide (Latest 2022/2023)

Brain metabolism o Soul source of energy for the brain is glucose. Brain needs glucose to function. Brain cannot store it, but needs a constant supply. If glucose levels start to fall you will some changed. o Cerebral glucose < 70 mg/dL = confusion o Cerebral glucose < 20 mg/dL = damage · Cerebral blood flow · Autoregulation o Changes in pressure o Changes in CO2 ▪ Alters cerebral blood volume with change in blood vessel size o Ability of the blood vessel in the brain to either constrict or dilate in response to pressure or CO2 levels ▪ Hypotension or hypoventilating causing hypercapnia BV in brain will dilate and vice versa try to send more blood and oxygen to brain. ▪ If hypertension or hypocapnia blood vessels in the brain will constrict. ▪ Systolic less than 50 or greater than 160 BV in brain lose the ability to autoregulate. Neuro Assessment o GCS, LOC, Memory, speech, Reflexes (babinski with brain injury) which only babies should have if adult has it this is not good, motor response, sensation , look for aphasia, motor strength ▪ Concerned with GAS or 8 or lower o Posturing ▪ Decorticate · Extremities go toward the body ▪ Decerebrate · Extremities pull away from the body, more severe, damage to brainstem – this is the worse posturing