CCRN Neurological Critical Care 2 — Questions and Answers
Question 1: 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)?
- 55 mmHg (Correct answer)
- 65 mmHg
- 105 mmHg
- 45 mmHg
Correct answer: 55 mmHg
CPP equals MAP minus ICP, so 80 minus 25 equals 55 mmHg.
Question 2: Which finding is the earliest and most sensitive indicator of increasing intracranial pressure?
- Change in level of consciousness (Correct answer)
- Fixed dilated pupils
- Cushing's triad
- Decerebrate posturing
Correct answer: Change in level of consciousness
A declining level of consciousness is the earliest and most sensitive sign of rising ICP.
Question 3: Cushing's triad, a late sign of increased ICP, consists of which combination?
- Hypertension with widening pulse pressure, bradycardia, and irregular respirations (Correct answer)
- Hypotension, tachycardia, and tachypnea
- Fever, tachycardia, and hypertension
- Hypotension, bradycardia, and apnea
Correct answer: Hypertension with widening pulse pressure, bradycardia, and irregular respirations
Cushing's triad is widening pulse pressure (rising systolic), bradycardia, and irregular respirations.
Question 4: A patient receiving mannitol for elevated ICP should be monitored most closely for which complication?
- Serum hyperosmolality and dehydration (Correct answer)
- Hyperkalemia
- Fluid overload and hyponatremia
- Metabolic acidosis
Correct answer: Serum hyperosmolality and dehydration
Mannitol's osmotic diuresis can cause dehydration and dangerously high serum osmolality.
Question 5: Which position is most appropriate to optimize cerebral venous drainage in a patient with increased ICP?
- Head of bed at 30 degrees with the head midline (Correct answer)
- Trendelenburg position
- Flat with the head turned to the side
- Prone with head elevated
Correct 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.
Question 6: A patient with a TBI suddenly develops polyuria with dilute urine, hypernatremia, and rising serum osmolality. Which condition is most likely?
- Diabetes insipidus (Correct answer)
- SIADH
- Cerebral salt wasting
- Acute tubular necrosis
Correct answer: Diabetes insipidus
Diabetes insipidus causes large volumes of dilute urine with hypernatremia from ADH deficiency.
Question 7: What is the primary goal of maintaining normocapnia (PaCO2 35-45 mmHg) in a patient with elevated ICP?
- To avoid cerebral vasoconstriction or vasodilation that worsens perfusion or pressure (Correct answer)
- To increase cerebral oxygen consumption
- To promote metabolic alkalosis
- To stimulate the respiratory drive
Correct 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.
CCRN Neurological Critical Care 2
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)?