Coma, Persistent Vegetative State, Brain Death

Question 1

what are some features of a coma patient?

Answer 1

unrousable psychological unresponsiveness
eyes closed
no psychologically understandable response to external stimula or inner need

Question 2

what does consciousness depend on?

Answer 2

intact ascending reticular activating system

functional cerebral cortex of BOTH hemispheres

Question 3

what does the ascending reticular activating system do?

Answer 3

acts as the alerting or awakening element of consciousness

Question 4

what does the cerebral cortex do with regards to consciousness?

Answer 4

determines the content of said consciousness

Question 5

what can cause a decreased GCS score?

Answer 5

toxic/metabolic states
seizures
damage to reticular activating system
causes of raised ICP

Question 6

what are examples of toxic/metabolic states?

Answer 6

hypoxia
hypercapnia
hypotension
drug intoxication/renal or liver failure
hypoglycaemia
ketoacidosis

Question 7

does focal damage to part of the cortex affect conscious level?

Answer 7

no

Question 8

what is persistent vegetative state?

Answer 8

a state in which the brainstem recovers to a considerable extent but there is no evidence of recovery of cortical function

Question 9

what are some features of persistent vegetative state?

Answer 9

arousal and wakefullness but no regaining of awareness of purposeful behaviour of any kind

Question 10

what is “locked in” syndrome?

Answer 10

total paralysis below the level of the third nerve nuclei

Question 11

what are some features of locked in syndrome?

Answer 11

patient able to open, elevate and depress eyes
no horizontal eye movement
no other voluntary eye movement

Question 12

how is locked in syndrome diagnosed?

Answer 12

recognise that patient can open eyes voluntarily and signal numerically by eye closure

Question 13

what can cause fluctuating respiration?

Answer 13

brainstem lesion

Question 14

what can cause depressed respiration?

Answer 14

drug OD

metabolic disturbance

Question 15

what can cause increased respiration

Answer 15

hypoxia
hypercapnia
acidosis

Question 16

what infection should you examine for when attempting to resuscitate a patient?

Answer 16

meningitis - treat on suspicion

Question 17

what should you establish when attempting to resuscitate a patient?

Answer 17

baseline BP
pulse
temperature
IV access
stabilise neck also

Question 18

how is a coma neurologically assessed?

Answer 18

using:
GCS
brainstem function
motor function and reflexes

Question 19

what GCS score would classify a patient as being in a coma?

Answer 19

less than or equal to 8

Question 20

what can cause a coma without focal or lateralising signs and without meningism?

Answer 20

ischaemic conditions
metabolic disturbance
intoxications
systemic infections
epilepsy
hyper/hypo thermia

Question 21

what investigations are appropriate for assessing coma patients?

Answer 21

toxicology screen
measure blood sugar and electrolytes
assess hepatic and renal function
measure BP
acid - base assessment and blood gases
CT head
Lumbar puncture

Question 22

what should you consider in a patient who is in a coma without focal or lateralising signs but with meningism?

Answer 22

subarachnoid haemorrhage
meningitis
encephalitis

Question 23

what can cause a coma WITH focal brainstem or lateralising cerebral signs

Answer 23

cerebral tumour
cerebral haemorrhage
cerebral infarction
cerebral abscess

Question 24

what investigations are obligatory in coma WITH focal brainstem or lateralising cerebral signs?

Answer 24

CT or MRI

Question 25

if CT or MRI are not diagnostic in come WITH signs then what investigations can be used to try and determine the cause of the coma?

Answer 25

metabolic screens
lumbar puncture
EEG

Question 26

what are the most common causes of coma lasting more than 5 hours?

Answer 26

40% drug ingestion with or without alchohol
25% due to hypoxia
20% due to cerebrovascular event
15% metabolic

Question 27

what are some factors that can help predict the outcome of a coma?

Answer 27

age
cause of coma
depth of coma
duration of coma
certain clinical signs such as brain stem reflexes

Question 28

what is important in continuing care of patients in a coma?

Answer 28

maintenance of vital functions
care of skin
attention to bladder and bowel function
control of seizures
prophylaxis of DVT and peptic ulceration
prevention of contractures
consider "locked in" syndrome

Question 29

what shape does a subdural haematoma take on CT?

Answer 29

ellipse shape/convex

Question 30

what shape does an extradural haematoma take on a CT?

Answer 30

concave

Question 31

how do you manage a head inury?

Answer 31

stabilise C spine
ABC
if GCS < 8 intubation and ventilation
treat raised ICP
neuro obs