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Y2 Neurology > Coma > Flashcards

Flashcards in Coma Deck (32)
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1
Q

what is the definition of a coma ?

A

a state of unrousable psychological unresponsiveness in which the subject lies with eyes closed and shows no psychological understandable response to external stimulus or inner need

2
Q

what two things does consciousness depend on?

A
  1. intact ascending reticular activating systems

2. cerebral cortex

3
Q

how is the ascending reticular activating systems involved in consciousness?

A

acts as the alerting element of consciousness

- arousal

4
Q

how is the cerebral cortex involved in consciousness?

A

determines the content of the consciousness

- awareness of environment

5
Q

state some causes of reduced GCS ?

A

toxic/metabolic states
- hypoxia, renal/liver failure, hypoglycaemia
seizures
damage to reticular activating systems
raised ICP
- tumour, stroke, EDH, SAH, hydrocephalus

6
Q

what is a vegetative state ?

A

patient has wakefulness but has very low awareness

- brain stem has recovered but cortical function is still damaged

7
Q

what is locked in syndrome?

A

the patient has high wakefulness and awareness but has total paralysis below third nerve nuclei so can only elevate and depress their eyes

8
Q

what could these different types of breathing suggest?

  • depressed
  • increased
  • fluctuating
A

depressed
- drug overdose, metabolic disturbance

increased
- hypoxia, hypercapnia, acidosis

fluctuating
- brain stem lesion

9
Q

what happens to respiration during hypoventilation?

A

fast, shallow breathes

  • low O2 inout and can’t blow off CO2 properly
  • CO2 builds up in blood
  • protons increase in the blood and causes acidosis
  • the central chemoreceptors detect the change and cause a decrease in respiration rate
10
Q

what should be examined and monitored for a coma patient

A
temperature 
heart rate 
BP 
CVS 
Resp. rate 
Breath smell
Meningism 
Abdominal problems
11
Q

what assessment is used to determine consciousness?

A

Glasgow coma score

12
Q

what are the three parts of the GCS?

A

eyes
verbal
motor

13
Q

how many points are available for eyes in GCS?

A

4

  • spontaneous
  • to sound
  • to pain
  • none
14
Q

how many points are available for verbal in GCS?

A

5

  • orientated
  • confused
  • inappropriate words
  • sounds
  • none
15
Q

how many points are available for motor in GCS?

A

6

  • obey commands
  • localising to pain
  • flexing towards pain
  • abnormal flexion towards pain
  • extending to pain
  • none
16
Q

what score classes a person in a coma?

A

less or equal to 8

17
Q

what nerves are involved in the pupillary reaction

A

optic and oculomotor

18
Q

what nerves are involved in the corneal reaction

A

trigeminal and facial

19
Q

what nerves are involved in the respiration pattern?

A

medullary centre

20
Q

what is meningism?

A

set of symptoms similar to those of meningitis but not caused by meningitis

21
Q

state some causes of coma without focal and meningism signs

A
  • anoxia
  • metabolic disturbances
  • intoxications
  • systematic infections
  • hyper/hypothermia
  • epilepsy
22
Q

state some causes of coma without focal but with meningism signs

A

SAH
Meningitis
Encephalitis

23
Q

state some investigations that should be done for a coma absent of focal and meningism signs ?

A
  • toxicology for alcohol levels
  • blood sugar and electrolytes
  • hepatic and renal function
  • ABG (arterial blood gases)
  • blood pressure
  • Carbon monoxide poisoning
24
Q

what investigations should be done if meningism symptoms are present in a coma patient ?

A

CT head scan

Lumbar puncture

25
Q

what are some causes of a coma with focal signs?

A

cerebral

  • tumour
  • haemorrhage
  • infarction
  • abscess
26
Q

what investigations should be done for a coma patient with focal signs ?

A
CT/MRI 
if scans are not diagnostic 
- metabolic screens 
- lumbar puncture 
- EEG
27
Q

what is the most common cause of a coma to last more than 5 hours ?

A

drug ingestion and alcohol

28
Q

what factors effect the outcome of a coma?

A
age 
cause of coma 
depth of coma 
duration of coma 
clinical signs
29
Q

what % of non traumatic coma patients will die or remain vegetative when in the coma >6hrs?

A

85%

30
Q

rank these from best to worst recovery for cause of coma?

  • hypoxic ischaemia
  • metabolic
  • cerebrovascular disease
A

metabolic
hypoxic ischaemia
cerebrovascular disease

31
Q

what secondary care must be thought about for patients in a coma?

A
  • care of skin
  • avoid pressure sores
  • attention to bladder and bowel function
  • control of seizures
  • prophylaxis of DVT
  • consider locked in syndrome
32
Q

how is a raised ICP managed ?

A
surgery to relieve pressure 
osmotic agents - mannitol
raise head to 40 degrees
reduce pain 
maintain good ventilation
reduce metabolism