Neurological Critical Care Flashcards

A patient with a severe traumatic brain injury has an ICP of 25 mmHg and a MAP of 80 mmHg. What is the cerebral perfusion pressure (CPP)?

Answer: 55 mmHg

CPP equals MAP minus ICP, so 80 minus 25 equals 55 mmHg.

Which finding is the earliest and most sensitive indicator of increasing intracranial pressure?

Answer: Change in level of consciousness

A declining level of consciousness is the earliest and most sensitive sign of rising ICP.

Cushing's triad, a late sign of increased ICP, consists of which combination?

Answer: Hypertension with widening pulse pressure, bradycardia, and irregular respirations

Cushing's triad is widening pulse pressure (rising systolic), bradycardia, and irregular respirations.

A patient receiving mannitol for elevated ICP should be monitored most closely for which complication?

Answer: Serum hyperosmolality and dehydration

Mannitol's osmotic diuresis can cause dehydration and dangerously high serum osmolality.

Which position is most appropriate to optimize cerebral venous drainage in a patient with increased ICP?

Answer: Head of bed at 30 degrees with the head midline

Elevating the head 30 degrees and keeping it midline promotes venous outflow and lowers ICP.

A patient with a TBI suddenly develops polyuria with dilute urine, hypernatremia, and rising serum osmolality. Which condition is most likely?

Answer: Diabetes insipidus

Diabetes insipidus causes large volumes of dilute urine with hypernatremia from ADH deficiency.

What is the primary goal of maintaining normocapnia (PaCO2 35-45 mmHg) in a patient with elevated ICP?

Answer: To avoid cerebral vasoconstriction or vasodilation that worsens perfusion or pressure

CO2 strongly affects cerebral vessel caliber, so normocapnia prevents harmful vasoconstriction or vasodilation.