Clinical Quick Reference Guides / ICP Fast Facts
MULTIPLE CHOICE TOPIC REVIEW / INCREASED ICP
Intercranial Pressure
Pressure within the cranial vault is measured in millimeters of mercury (mm Hg). Normally this pressure is less than 20 mm Hg.
The cranium is a rigid structure containing 3 main components. These components are blood, the brain, and cerebrospinal fluid. If there is an increase in either of these contents, the patient will experience an increase in the pressure within the cranial vault.
Monroe-Kellie Doctrine
This doctrine states that the cranium vault contents are fixed.
If a patient experiences an increase in volume of one of the cranium components, the result will be a decrease in volume of one or two of the other components.
This can lead to an alteration in cerebral blood flow, and/or herniation of the brain.
Cushing Triad
This is well-noted clinical syndrome that comprises clinical signs of hypertension, bradycardia, and irregular respiration. These signal impending brain herniation.
It occurs when ICP is too high. The increase in blood pressure is a reflex mechanism to maintain cerebral perfusion pressure. High blood pressure precipitates a reflex bradycardia and brain stem compromise affects respiration.
In the end, the cranium contents are displaced downward due to the elevations in ICP. Potentially fatal herniation may follow if prompt care, evaluation and treatment are unsuccessful.
Greg
Case Study:
Greg Wynn is a 57 yr old male with a PMH of inoperable brain cancer, admitted now for increased ICP to the cancer specialty facility.
1.) Which of the following unit patients is MOST risk for increased intracranial pressure?
A. A 22 yr old male s/p 2 days post-op laser eye surgery.
B. A 65 yr old female diagnosed with myocardial infarction.
C. A 18 yr old with current diagnoses of glioblastoma.
D. A 47 yr old female newly diagnosed with IBD.
2.) Identify the structure(s) below that can directly impact and alter intracranial pressure:
A. Blood
B. Brain
C. CSF
D. None of the above.
3.) Greg is at risk for significant impacts related to increased intracranial pressure. What type of activity or activities should he avoid?
A. Speaking
B. Coughing
C. Valsalva maneuver
D. All of the above.
4.) You are caring for Greg, diagnosed with increased intracranial pressure. Which of the following trends in vital signs is most associated with rising ICP?
A. Decreasing temperature, increasing pulse, decreasing respirations, increasing blood pressure.
B. Increasing temperature, decreasing pulse, increasing respirations, decreasing blood pressure.
C. Increasing temperature, decreasing pulse, decreasing respirations, increasing blood pressure.
D. None of the above.
Answers follow at the end of this post.
Clinical Quick Reference Monthly is a study resource and is not intended to be medical advice. Always follow the advice of your institution and providers.
Resources: CDC, NIH
Answers: 1-c; 2-a,b,c; 3-b,c; 4-c