Intracranial HTN and Brain death

Question 1

Formula for cerebral perfusion pressure

Answer 1

CPP = MAP - ICP

Question 2

Goal cerebral perfusion pressure

Answer 2

50-70

Question 3

Max normal ICP

Answer 3

15 mmHg

Question 4

2 prophylactic treatments to lower ICP

Answer 4

Elevate head of bed to 30 degrees

Prophylactic seizure medication for 7 days if TBI

Question 5

2 things that do not effect ICP

Answer 5

Sedation/paralysis

Fever control

Question 6

In elevated ICP, what CO2 abnormality should you avoid

Answer 6

Hypercapnia

Question 7

If a patient is getting hyperventilation treatment for ICP, how long does the effect of that last

Answer 7

about an hour

Question 8

What is the main side effect of hyperventilation for ICP

Answer 8

Vasoconstricts the brain vessels which reduces blood flow (could cause stroke)

Question 9

When doing therapeutic hypothermia for ICP, what should you keep the CO2 above

Answer 9

30

Question 10

What is the main side effect of mannitol

Answer 10

Renal failure

Question 11

What is the target osmolarity when using mannitol for ICP

Answer 11

320

Question 12

What are the 3 side effects of hypertonic saline for ICP

Answer 12

Pulmonary edema

Hyperchloremic acidosis

Vein sclerosis

Question 13

What is the target osmolarity when using hypertonic saline for ICP

Answer 13

320 but also sodium < 155

Question 14

Only cause of increased ICP that steroids are indicated for

Answer 14

tumorogenic edema

Question 15

Do barbituates or hypothermia lower ICP

Answer 15

Yes but no clinical benefit in studies

Question 16

Do you do craniotomy early or late for ICP

Answer 16

Late (after medical therapy fails)

Literature shows worsening outcomes with early craniotomy

Question 17

6 criteria to begin brain death exam

Answer 17

Known cause of brain injury

Off of all sedatives and paralytics by 5 half lives

No major metabolic or electrolyte derrangements

Normothermic

Not in shock

> 24 hours since cardiac arrest

Question 18

Do spinal reflexes count as response to noxious stimuli in brain death exam

Answer 18

no

Question 19

6 requirements of brain death exam

Answer 19

Unresponsive to noxious stimuli (spinal reflexes don’t count)

No pupil response

No response to oculocephalic or oculovestibular testing

No corneal relfex

No gag or cough

Apnea

Question 20

Requirements for positive apnea test in brain death exam

Answer 20

Initial PCO2 normal range

No evidence of chronic hypercapnia

100 oxygen during the test (abort if hypoxemia develops)

Observe for 10 minutes

ABG post has to have PCO2 > 60 or a 20 point rise from baseline