Intracranial Pressure Flashcards
Skull has three essential components
Brain tissue
Blood Cerebrospinal fluid (CSF)
Intracranial Pressure
The degree to which these factors ↑ ICP
depends on the ability of the brain to
compensate for the changes
Intracranial Pressure
Factors that influence ICP
- Arterial pressure
- Venous pressure
- Intra-abdominal and intrathoacic pressure
- Body position
- Temp
- Blood gases (CO2 & O2)
mechanism of increased ICP
- Mass lesion
- Cerebral edema
- Head injury
- Brain inflammation
- Metabolic insult
IICP complications
Two major complications of uncontrolled high ICP
- Inadequate cerebral perfusion
- Cerebral herniation
Herniation syndromes Supratentorial herniation
Uncal
- Uncuss or hippocampal gyrus (or both) shift from the middle fossa through the tensorial notch into the posterior fossa
Central
- Downward shift of the diencephalon through the tensorial notch
Cingulate
- Cingulate gyrus shifts under the flax cerebri
Herniation syndromes
Infreatentorial herniation
Cerebellar tonsil shifts through foramen magnum
IICP Clinical manifestations
- Change in level of consciousness
- Changes in vital signs (Cushing triad)
- Bradycardia
- Irregular resps
- Ocular signs (papilledem)
- Decreases in motor function
- Headache
- Vomiting
What is Cushing triad
Cushing’s triad is a clinical syndrome that consists of three classic signs, which indicate increased intracranial pressure (ICP) and potential brain herniation.
Hypertension
- Particularly the systolic pressure, as the body tries to maintain cerebral perfusion
Bradycardia
Irregular respirations
Decerebrate posturing (extensor)
Abnormal body posture due to severe brainstem injury (below the red nucleus).
Arms: Extended, straight, and rotated inward.
Legs: Extended, internally rotated, feet pointed downward (plantar flexion).
Significance: Indicates serious brain damage, often worse than decorticate posturing.
Causes: Traumatic brain injury, stroke, brain tumor, infections.
Prognosis: Typically poor, requires immediate medical attention.
