Neuro Exam Study Guide Spring A GRADED

Intracranial Pressure and Head Injuries A. Factors that influence ICP a. Arterial and Venous pressure b. Intraabdominal and intrathoracic pressure c. Posture- Patient should not be lying flat (positioning important) 30 degrees with head in the midline d. Temperature- Keep room temp (Avoid shivering and rigors) e. Blood gases – Co2 dilates blood vessels which increase volume of blood in brain and increase ICP B. Important Values a. Normal ICP 5 to 15 mmHg- Elevated if > 20 mmHg b. Measured with a pressure transducer –ventriculostomy c. Cerebral Blood Flow- amount of blood in mL passing through brain tissue i. 50mL/min per 100g of brain tissue d. Maintenance of blood flow to the brain is critical i. Brain requires 20% of body’s Oxygen ii. 25% of body’s Glucose e. Cerebral Perfusion pressure (CPP) Normal is 60 to 100mmHg i. CPP=MAP-ICP ii. MAP= SBP + 2(DBP)/3 iii. <50 mmHg is associated with ischemia and neuronal death iv. <30mmHg incompatible with life C. Clinical Manifestations