ITU Learnig

Question 1

What is malignant MCAu

Answer 1

Brain oedema and can lead to coming After MCA middle cerebral artery infarct - due to being quite a significant area of brain infarcted can result in significant enough oedema

Can also happen with posterior fossa strokes because they are in their own dura can result in coning

Question 2

What does VVI mean on a pacemaker ?

Answer 2

Ventricle paced , ventricle sensed
If sensed a rhythm, the pacing is inhibited
Otherwise run a risk of delivering shock during repolarisation and risk of VF

Question 3

What are the types of brain injury after insult

Answer 3

primary brain injury - at the time e.g. bleeding, ischaemia

secondary - hours to days after. due to inflammation, ROS, inflammatory agents, increased metabolism, can lead to oedema, further ischaemia.

Question 4

how are Traumatic brain injuries classified?

Answer 4

by GCS
mild- 13-15
moderate 9-12
severe 8 or les

Question 5

what are the 4 Ts of HIT?

Answer 5

Timing - needs to be 5-10 days OR previous HIT - time for Ab to develop
thrombocytopenia - to what extent e.g. 50% or more
thrombosis
other causes of thrombocytopenia ruled out

out of 8
the higher, the more likely

HIT is RARE

Question 6

what happens to platelets in an acute illness?

Answer 6

increase initially - reactive
then consumed - microthombi
by the time they get to critical care/ hospital - often low

Question 7

why are cephalosporins used for meningitis?

Answer 7

small and lipid soluble - can cross BBB and act centrally

when there is meningitis and inflammation of the brain, there may be some disruption of BBB and some other Abx may also have partial efect

Question 8

what is coronary steel? how is this linked to inhalation agents?

Answer 8

Coronary steel is a phenomenom seen in IHD
atherosclerosed coronary vessels are narrowed and thus maximally dilated to compensate for this narrowing

general vasodilation of the coronary bed will dilate other coronary vessels more than the diseased ones (because they are already max dilated) and therefore this will result in flow away from the diseased vessels and towards healthier areas of the heart

this can worsen ischaemia to these regions

isoflurane has strong vasodilatory effects on coronary vessels and thus is linked to coronary steel. sevoflurane and des also cause vasodilation however not to the same extent so are not as implicated. halothane actually causes constriction of coronarys.

however isofluranes protective role in promoting ischaemic preconditioning (pathways that protect heart from ischaemia e.g. release of NO, mitochondrial stabilisation etc) means the clinical relavance of coronary steel is low. In fact for cardiac bypass surgery, isoflurane is often the selected agent.

Question 9

State the GCS score

Answer 9

Assessment of neurological function
Score from 3 to 15
With 15 representing normal neurological function

Eyes
4- spontaneous
3- voic
2 - pain
1- none

Voice
5- orientated
4 - confused
3 - inappropriate words
2- sounds
1 - none

Motor
6 - purposeful movements / follows instruction
5 - localised to pain
4- withdraws from pain
3- flexes to pain
2- extends to pain
1 - no movement

Question 10

Tell me about neuroprognostication…

Answer 10

This is the process of predicting neurological outcome or recovery after a brain injury (stroke, trauma, cardiac arrest)

Helps guide ITU care, give families an idea of future outlook .

• Timing *
  It should only be done after a period of physiological stability e.g. 72 hours after period of normotension, normothermia, normoglycaemia etc

Assessment
Differnt modalities to improve probability of accuracy of prediction e,g clinical (GCS, reflexes ), imaging, EEG, SSEPs , NSE
(GCS - particularly motor assessment)

Question 11

How is neuroprognostication assessed clinically ?

Answer 11

GCS
In particularly motor response to pain
E.g pain - sternal rub or supraorbital pressure
Flexion / extension of limbs suggests poor outcome and global injury

Corneal reflex
Pupil reflex
Cough reflex - coughing on tube or can be properly assessed

Question 12

What is an NSE test

Answer 12

Neuro specific enolase
Brain enzyme raised in injury
Used as a marker

Question 13

What are SSEPs

Answer 13

Somatosensory evoked potentials
Usually small current placed on median nerve to stimulate a sensory response in cortex which is measured

Question 14

How can EEGs be used in neuroprognostication

Answer 14

Burst suppression
Or suppressed background activity

Question 15

What could confound neuroprognostication

Answer 15

Sedation
Neuromuscular blockers
Abnormalities in physiology e.g hypoglycaemic, hypothermia, sepsis

Question 16

What are the causes of sterile sepsis ?

Answer 16

Sterile sepsis I.e no infective cause
Pancreatitis
Haem malignancy
Serotonin syndrome