Intracranial HTN and Brain death Flashcards
Formula for cerebral perfusion pressure
CPP = MAP - ICP
Goal cerebral perfusion pressure
50-70
Max normal ICP
15 mmHg
2 prophylactic treatments to lower ICP
Elevate head of bed to 30 degrees
Prophylactic seizure medication for 7 days if TBI
2 things that do not effect ICP
Sedation/paralysis
Fever control
In elevated ICP, what CO2 abnormality should you avoid
Hypercapnia
If a patient is getting hyperventilation treatment for ICP, how long does the effect of that last
about an hour
What is the main side effect of hyperventilation for ICP
Vasoconstricts the brain vessels which reduces blood flow (could cause stroke)
When doing therapeutic hypothermia for ICP, what should you keep the CO2 above
30
What is the main side effect of mannitol
Renal failure
What is the target osmolarity when using mannitol for ICP
320
What are the 3 side effects of hypertonic saline for ICP
Pulmonary edema
Hyperchloremic acidosis
Vein sclerosis
What is the target osmolarity when using hypertonic saline for ICP
320 but also sodium < 155
Only cause of increased ICP that steroids are indicated for
tumorogenic edema
Do barbituates or hypothermia lower ICP
Yes but no clinical benefit in studies
Do you do craniotomy early or late for ICP
Late (after medical therapy fails)
Literature shows worsening outcomes with early craniotomy
6 criteria to begin brain death exam
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
Do spinal reflexes count as response to noxious stimuli in brain death exam
no
6 requirements of brain death exam
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
Requirements for positive apnea test in brain death exam
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
