4. Brain Resus

Question 1

How much of CO and oxygen percent of total body does brain get?

Answer 1

CO - 15%
O2 percent 20%

Question 2

Elevated ICP causing cerebral edema - how does this occur?

Answer 2

Elevated intracranial pressure can result in ischemia
This ischemia leads to failure of oxidative phosphorylation and leads to inability to maintain ATP, thus osmotic gradient failure
Increased intracellular osmolarity means influx of water and Cytotoxic edema then leads to brain secondary injury

Question 3

Monro Kellie doctrine

Answer 3

Increasing cerebral edema volume means that in a finite space, other components of brain volume must decrease (3 components: brain, blood, csf)

Question 4

How does Monroe Kellie doctrine actually play out?

Answer 4

Shift IC to subarachnoid
Reduction of fluid in cerebral veins and dural sinuses

Question 5

In final stages, how does ICP progress?

Answer 5

Herniation cerebellar tonsil through formed magnum and compresses medulla

Question 6

CPP= ? - ?

Answer 6

MAP - ICP

Question 7

CPP = MAP - ICP how does an incr in ICP compensate… and then become a viscous cycle?

Answer 7

Cerebral arteriolar vasodilation for decr MAP
When then can actually just increase further blood volume and increase ICP

Question 8

How long do studies recommend before using neuro exam for prognostication?

Answer 8

72 hours

Question 9

Elevated ICP: how to manage initial pain, fever, normothermia?

Answer 9

Fentanyl 25-50 mcg q5h PRN
Avoid coughing so procedurally sedate with propofol
Ongoing ICP despite these? Pentobarbital
If spikes in ICP and active herniation consider mannitol if fluid overload (0.25-1g/kg) q6h for serum osmol of 320 goal or need resus fluid 3% hypertonic saline 30-60ml q6h to aim for sodium of max 160

Question 10

If seizure with ICP increase, how to manage

Answer 10

Regular - lorazepam 0.1mg/kg up to 4mg
Continues; second line agent of Keppra, VPA, fospheny

Question 11

Not really clear in tbi prophylaxis: if used, what and what dose?

Answer 11

Keppra 500mg po tid

Question 12

ICH seizure prophylaxis yes or no?

Answer 12

No

Question 13

In the event of cardiac arrest, what is the first priority of cerebral resus?

Answer 13

rosc

depndent on complete and relative ischemia to brain

Question 14

What is cerebral autoregulation?

Answer 14

change in SBP causes change to cerebrovasulcar resistance to keep cerebral blood flow at certain level over wide range of arterial BP

Question 15

MAP and SBP goal for ICP pt

Answer 15

Map >65
sbp >90 cardiac arrest

Question 16

ICH - goal BP?

Answer 16

<140 but <160 if controlled chronic HTN who are severe HTN on presentation

Question 17

How does hyperventilation quickly lower ICP?

Answer 17

CO is potent vasoactive agent that lowers CO arterial partial pressure to reduce cerebral blood flow 2% q1mmHg decrease in paco2

Question 18

Paco2 goal in hyperventilation to maintain ICP?

Answer 18

35-40

Question 19

Goal O2 in ICP

Answer 19

pao2 80-120mmhg with o2 sat high 90s on lowest fio2 possible

Question 20

CT findings of intracranial HTN?

Answer 20

compressed basal cistern
disffuse sulcal effacement
diffuse loss of differentiation grey and white matter

Question 21

Suggestive clinical features ICP

Answer 21

papilledema
bilateral sixth nerve palsy
new third n palsy if comatose

Question 22

Which level of ICP has been associated with worse neuro outcomes and should trigger treatment?

Answer 22

> 22

Question 23

Best management steps for general ICP: 5

Answer 23

1. Position pt head up to 30 deg
2. Neutral head and neck to avoid JV compression
3. Tx fever with antipyretic for temp </=37
4. Minimize triggers of ICP increase (like suction, freq turning) - meds for sedation
5. Osmolar therapy if required

Question 24

If ICP pt has a ventriculostomy how to manage?

Answer 24

clamp to get cont ICP measure but if elevated unclamp to decrease ICP

Question 25

Tx cases of refractory ICP with what 2 options?

Answer 25

1. Cont pentobarbital infusion
2. Mild induced hypothermia (32-36). Avoid rapid rewarm

Question 26

Surgical tx of ICP

Answer 26

if refracotry in TBI - decompressive craniectomy

Question 27

If temp in a an incr ICP pt goes up above 38, how to tx?

Answer 27

acetaminophen

surface cooling

Question 28

What clinical finding indicates poor outcome with low FP rate and narrow confidence interval at 72 h after ICP?

Answer 28

bilateral absent pupillary light reflex

Question 29

Additional features (than bilat absent pupillary light reflex) of poor px in pt with Inc ICP?

Answer 29

absent corneal reflex
absent reactivity or burst suppression pattern on eeg
myoclonic status epi
diffuse anoxic injury on ct/mri

Question 30

nresponsive survivors of out-of-hospital cardiac arrest should have rapid initiation of targeted temperature management (TTM) in the emergency department and be maintained at a constant target of __ to __ C in an ICU setting for 24 h after resuscitation.

Answer 30

33-36