Coma

Question 1

what is the definition of a coma ?

Answer 1

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

Question 2

what two things does consciousness depend on?

Answer 2

1. intact ascending reticular activating systems

2. cerebral cortex

Question 3

how is the ascending reticular activating systems involved in consciousness?

Answer 3

acts as the alerting element of consciousness

- arousal

Question 4

how is the cerebral cortex involved in consciousness?

Answer 4

determines the content of the consciousness

- awareness of environment

Question 5

state some causes of reduced GCS ?

Answer 5

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

Question 6

what is a vegetative state ?

Answer 6

patient has wakefulness but has very low awareness

- brain stem has recovered but cortical function is still damaged

Question 7

what is locked in syndrome?

Answer 7

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

Question 8

what could these different types of breathing suggest?

• depressed
• increased
• fluctuating

Answer 8

depressed
- drug overdose, metabolic disturbance

increased
- hypoxia, hypercapnia, acidosis

fluctuating
- brain stem lesion

Question 9

what happens to respiration during hypoventilation?

Answer 9

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

Question 10

what should be examined and monitored for a coma patient

Answer 10

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

Question 11

what assessment is used to determine consciousness?

Answer 11

Glasgow coma score

Question 12

what are the three parts of the GCS?

Answer 12

eyes
verbal
motor

Question 13

how many points are available for eyes in GCS?

Answer 13

4

• spontaneous
• to sound
• to pain
• none

Question 14

how many points are available for verbal in GCS?

Answer 14

5

• orientated
• confused
• inappropriate words
• sounds
• none

Question 15

how many points are available for motor in GCS?

Answer 15

6

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

Question 16

what score classes a person in a coma?

Answer 16

less or equal to 8

Question 17

what nerves are involved in the pupillary reaction

Answer 17

optic and oculomotor

Question 18

what nerves are involved in the corneal reaction

Answer 18

trigeminal and facial

Question 19

what nerves are involved in the respiration pattern?

Answer 19

medullary centre

Question 20

what is meningism?

Answer 20

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

Question 21

state some causes of coma without focal and meningism signs

Answer 21

• anoxia
• metabolic disturbances
• intoxications
• systematic infections
• hyper/hypothermia
• epilepsy

Question 22

state some causes of coma without focal but with meningism signs

Answer 22

SAH
Meningitis
Encephalitis

Question 23

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

Answer 23

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

Question 24

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

Answer 24

CT head scan

Lumbar puncture

Question 25

what are some causes of a coma with focal signs?

Answer 25

cerebral

• tumour
• haemorrhage
• infarction
• abscess

Question 26

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

Answer 26

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

Question 27

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

Answer 27

drug ingestion and alcohol

Question 28

what factors effect the outcome of a coma?

Answer 28

age 
cause of coma 
depth of coma 
duration of coma 
clinical signs

Question 29

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

Answer 29

85%

Question 30

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

• hypoxic ischaemia
• metabolic
• cerebrovascular disease

Answer 30

metabolic
hypoxic ischaemia
cerebrovascular disease

Question 31

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

Answer 31

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

Question 32

how is a raised ICP managed ?

Answer 32

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