Acute Intracranial Problems

Question 1

What is the normal ICP

Answer 1

5-15mmHg

A sustained pressure over 20 mmHg must be treated.

Question 2

What is the nomal CPP (cerebral perfusion pressure)

Answer 2

60-100mmHg
less than 50 = ischemia, neuronal death
less than 30 = incompatable with life

Question 3

How can you calculate CPP?

Answer 3

MAP-ICP=CPP

Question 4

How do you calculate MAP

Answer 4

(Diastolic X 2) + Systolic / 3

Question 5

What is CPP

Answer 5

The pressure needed to ensure blood flow to the brain by adjusting the diameter of the cerebral vessels. This is affected by oxygenation, cerebral blood flow, BP, cerebral edema, and ICP.

Question 6

What is autoregulation?

Answer 6

is how your body insures proper blood flow to the brain. If we have an increase in ICP autoregulation makes it worse.

Question 7

What are some causes of increased ICP?

Answer 7

1. Space occupying leisons- tumor, abscess, hematomas, brain bleed. Thiese put pressure on the brain wish decreases blood flow and increases toxic waste. This increases our systemic blood pressure because the brain isnt being perfused enough
2. CSF Obstruction: hydrocephalus
3. Cerebral edema: Head trauma, ischemic stroke, hepatic encephalopathy, postop edema, and low sodium.
4. Meningitis or encephalitis: Pus build up on the brain decreases blood flow and increase ICP. Then we have toxic build up, are cerberal a dilate because of low oxygen, and our systemic blood pressure increases because we are not perfusing the brain properly.
5. Metabolic disorders: Hyponatremia, brain swelling
6. Increase in abdominal /chest pressure, Valsalva, suctioning, coughing, or posturing,
7. Vasodilation: Acidosis: low pH and CO2 are potent vasodilators
8. Increase in metabolic demand-Fever: This increases cellular metabolism, we burn through more oxygen, we get toxin build up, and increase ICP.

Question 8

What is a short term answer to quickly decrease ICP

Answer 8

Hyperventilation will help temporarily to decrease CO2 and thus decrease ICP but can also lead to ischemia form vasoconstriction

Question 9

What is the first symptom of increase ICP

Answer 9

A change in LOC

Question 10

What is cushings Triad?

Answer 10

With a loss of autoregulation the body attempts to maintain cerebral perfusion by increasing systolic BP (to push pass the blockage), with a widening pulse pressure (Pressure on the heart decreases the HR and lowers diatsolic P), and bradycardia with a full and bounding pulse and altered respirations/ bradypena (Increase P on the medulla decreases the effectivenss of the phrenic N, decreases RR).

Question 11

What are some exmples of a change in LOC

Answer 11

Agitation
Solmenelence
Dowsiness

Question 12

Why would a pt with an increase in ICP run a temp?

Answer 12

Edema puts pressure on the hypothalamus.