Traumatic Brain Injury

Question 1

normal level of intracranial pressure (ICP)

Answer 1

10 - 15 mm Hg

Question 2

cerebral perfusion pressure (CPP)

Answer 2

1. pressure gradient over which the brain is perfused
2. CPP = MAP - ICP
3. normal CPP > 70 mmHg
4. <60 mmHg = cerebral ischemia ->seizures -> coma -> death

Question 3

Increased cranial pressure s/s

Answer 3

1. ↓ LOC (lethargy-coma)
2. behavior changes (restlessness, irritability, confusion)
3. HA
4. N/V (may be projectile)
5. Change in speech pattern
   - aphasia
   - slurred speech
6. seizures - usually w/in first 24 hours)
7. Change in sensorimotor status
   - pupillary changes - dilated and unreactive/contricted and nonreactive
   - cranial nerve dysfunction
   - ataxia (loss of control of bodily movements)
8. Cushing’s Triad
   - severe hypertension
   - widened pulse pressure
   - bradycardia
9. Abnormal posturing
   - decerebrate (extensor)
   - decorticate (flexion)

Question 4

Cushing’s Triad

Answer 4

classic, but LATE sign of ⇡ICP

• severe hypertension
• widened pulse pressure (⇡ difference between systolic/diastolic)
• bradycardia

Question 5

normal ICP

Answer 5

10-15 mmHg

Question 6

What actions/situations can ⇡ ICP?

Answer 6

• hypercarbia
• ETT or oral tracheal suctioning
• coughing
• extreme neck or hip flexion/extension
• HOB lower than 30 degrees
• ⇡ing intra-abdominal pressure – restrictive clothing; Valsalva maneuver