coma, persistent vegetative state and brain death Flashcards

1
Q

Define coma

A

A state of unrousable psychological unresponsiveness in which the subjects lie with eyes closed and show no psychologically understandable response to external stimulus or inner need

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2
Q

What 2 things does consciousness rely on

A

intact ascending reticular system

Functioning cerebral cortex

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3
Q

What is the ascending reticular activating system responsible for?

A

awakening and alerting element of consciousness

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4
Q

What is the functioning cerebral cortex responsible for?

A

content of that consciousness - awareness

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5
Q

What GCS score(s) is defined as a coma

A

less than 8

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6
Q

Causes of decreased GCS

A

sepsis, hypoxia, hypotension,
drug intoxication, renal failure
hypoglycaemia
seizures, damage to reticular activating system
Raised ICP eg hydrocephalus, tumour, stroke, haemorrhage

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7
Q

What is persistent vegetative state?

A

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

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8
Q

What is the locked in syndrome?

A

The patient has total paralysis below the level of the 3rd nerve nuclei and can open, elevate and depress eyes although no horizontal eye movement and no other voluntary movement

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9
Q

Give an example of when locked in syndrome could occur

A

Stroke in basilar artery denying pons of blood supply

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10
Q

Breathing - what does fluctuating breathing and depressed respiration suggest?

A

fluctuating - brainstem lesion

depressed - drug overdose

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11
Q

First resuscitation and investigation of patient

A

ABC

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12
Q

Circulation - investigations

A

blood - glucose, biochemistry, haematology, blood gas and toxicology
blood pressure, pulse, temperature, IV access, stabilise neck
MENINGITIS

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13
Q

What is always important to discount in a coma patient?

A

meningitis

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14
Q

3 types of history for coma

A

expected progression eg renal failure
unpredictable with no known cause
unexpected eg head injury

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15
Q

Some monitoring of the patient would include..

A
temperature 
respiratory and heart rate 
bp
abdomen 
meningism 
fundal examination
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16
Q

meningism triad

A

neck stiffness
photophobia
headache

17
Q

3 neurological assessment of coma

A

GCS
brainstem function
motor function and reflexes

18
Q

How would you test brainstem function?

A

pupillary reaction, spontaneous eye movement, corneal response, occulovestibular response, respiratory pattern, dolls eye

19
Q

Testing motor function and reflexes

A

motor response
muscle tone
tendon reflexes
seizures

20
Q

GCS - 3 parts

A

eye opening
best verbal response
best motor response

21
Q

GCS - eye opening grading

A
4 = spontaneous 
3 = to voice 
2 = to painful stimuli 
1 = none
22
Q

GCS - best verbal response grading

A
5 - orientated 
4 - confused 
3 - inappropriate 
2 - incomprehensible sounds 
1 - none
23
Q

GCS - best motor response grading

A
6 = obey commands 
5 = localise to pain 
4= withdraw from pain 
3= flex
2= extend
1= none
24
Q

For each of the 3 categories what score represents a coma?

A

eyes - 2 or less
voice - 2 or less
motor - 4 or less

25
Q

Causes of coma without focal signs or meningism

A

anoxia, seizure/epilepsy, ischaemia, intoxications, metabolic disturbances, systemic infections, hyper/hypothermia

26
Q

Investigation of coma without focal signs or meningism

A
toxicology screen - alcohol 
blood sugar and electrolytes 
hepatic and renal function 
blood gas and acid base assessment 
blood pressure 
CO poisoning
27
Q

3 main causes of coma without focal signs but with menigism

A

subarachnoid haemorrhage
meningitis
encephalitis

28
Q

Investigation of coma with menigism only

A

CT head

lumbar puncture

29
Q

4 things to look for in lumbar puncture in coma with meningism

A

cell count
capsular antigen test
glucose level
appearance

30
Q

4 main causes of coma with focal brainstem or lateralising cerebral signs

A

cerebral tumour, haemorrhage, infarction or abscess

31
Q

Investigation of coma with focal signs

A

MRI/CT

metabolic screen, lumbar puncture, EEG

32
Q

Medical causes of coma lasting more than 5 hours

A

drug/alcohol ingestion
hypoxia eg MI
haemorrhage eg infarction
metabolic eg diabetes

33
Q

Prognostic factors in coma outcome

A
age 
cause of coma 
depth of coma 
duration of coma
clinical signs
34
Q

Continuing care of patients in a coma includes

A
maintain vital functions 
care of skin and avoid pressure sores 
prophylaxis of DVT 
bladder and bowel 
control seizures and prevent contractures 
consider locked in syndrome
35
Q

Why can head injury lead to focal neurological signs?

A

diffuse axonal injury
contusion - bruising
intracerebral haematoma
extracerebral haematoma eg extradural and subdural

36
Q

How to manage head injury

A
stabilise cervical spine 
ABC 
GCS - intubate and ventilate 
treat raised ICP 
cranial imaging 
neuro observations
37
Q

How to treat raised ICP

A
surgery to relieve pressure 
osmotic agent eg mannitol 
head at angle for venous return 
reduce pain 
maintain good PO2 and reduce PCO2 
reduce metabolism eg barbiturates