Coma, Persistent Vegetative State, Brain Death

Question 1

What is a coma?

Answer 1

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

Question 2

What is used to assess a coma?

Answer 2

Glasgow coma scale (GCS)

Question 3

What does GCS stand for?

Answer 3

Glasgow coma scale

Question 4

What are the 3 responses assesses in the GCS?

Answer 4

Eye opening response

Verbal response

Motor response

Question 5

Describe the scores for the eye opening response part of the GCS?

Answer 5

Question 6

Describe the scores for the verbal response part of the GCS?

Answer 6

Question 7

Describe the scores for the motor response part of the GCS?

Answer 7

Question 8

What are the 3 classes of injury from the GCS?

Answer 8

Minor brain injury

Moderate brain injury

Severe brain injury

Question 9

What points on GCS is minor brain injury?

Answer 9

13-15

Question 10

What points on GCS is moderate brain injury?

Answer 10

9-12

Question 11

What points on GCS is severe brain injury?

Answer 11

3-8 points

Question 12

What does consciousness depend on?

Answer 12

• Intact ascending reticular activating system to act on the alerting or awakening element of consciousness
  
  • (arousal)
• A functioning cerebral cortex of both hemispheres which determines the content of that consciousness
  
  • (awareness of environment)

Question 13

What are some causes of decreased GCS?

Answer 13

• Toxic/metabolic states
  
  • Hypoxia/hypercapnia/sepsis/hypotension
  • Drug intoxication/renal or liver failure
  • Hypoglycaemia, ketoacidosis
• Seizures
• Damage to reticular activating system
• Causes of raised intracranial pressure
  
  • Tumour, stroke, EDH (epidural haemorrhage), SDH (subdural haemorrhage), SAH (subarachnoid haemorrhage), hydrocephalus

Question 14

What are some causes of raised ICP?

Answer 14

• Tumour, stroke, EDH (epidural haemorrhage), SDH (subdural haemorrhage), SAH (subarachnoid haemorrhage), hydrocephalus

Question 15

What can cause toxic/metabolic stress and lead to decrease in GCS?

Answer 15

• Hypoxia/hypercapnia/sepsis/hypotension
• Drug intoxication/renal or liver failure
• Hypoglycaemia, ketoacidosis

Question 16

What can increased respiration be due to?

Answer 16

Hypoxia

Hypercapnia

Acidosis

Question 17

What can depressed respiration be due to?

Answer 17

Drug overdose

Metabolic disturbance

Question 18

What can fluctuating respiration be due to?

Answer 18

Brainstem lesion

Question 19

What blood samples should be done for patients who go into a coma?

Answer 19

• Glucose, biochemistry, haematology, blood gas
• Toxicology

Question 20

What are some causes of a patient going into a coma?

Answer 20

• Predictable progression of underlying illness
• Unpredictable event in patient with previously known disease
• Totally unexpected event
  
  • Head injury, sudden collapse, limb twitching, previous history of drug or alcohol abuse

Question 21

What parts of examination are important for coma?

Answer 21

• Temperature
• Heart rate, blood pressure, CVS
• Respiration
• Skin, breath
• Abdomen
• Meningism
• Fundal examination

Question 22

What parts of neurological assessment are important for coma?

Answer 22

• Glasgow coma scale
• Brainstem function
• Motor function and reflexes
  
  • Motor response
  • Muscle tone
  • Tendon reflexes
  • Seizures

Question 23

How is brianstem function tested?

Answer 23

Question 24

What is useful for establishing the causes of a coma?

Answer 24

Tabulate coma, meningism and focal brainstem or lateralising cerebral signs

Question 25

Coma without focal or lateralising signs and without meningism could be due to?

Answer 25

* Anoxic/ischaemic conditions * Metabolic disturbances * Intoxications * Systemic infections * Hyperthermia/hypothermia * Epilepsy * Investigations to determine this

Question 26

What investigations can be done to determine the cause of a coma without focal or lateralising signs and without meningism?

Answer 26

* Toxicology screen including alcohol level * Measure blood sugar and electrolytes * Assess hepatic and renal function * Acid-base assessment and blood gases * Measure blood pressure * Consider carbon monoxide poisoning

Question 27

Coma without focal or lateralising signs but with meningism (clinical syndrome of headache, neck stiffness and photophobia, often with nausea and vomiting) could be due to what?

Answer 27

* Subarachnoid haemorrhage * Meningitis * Encephalitis

Question 28

What investigations could be done to determine the cause of a coma without focal or lateralising signs but with meningism?

Answer 28

* CT head scan * Lumbar puncture * Appearance, cell count, glucose level, capsular antigen tests

Question 29

What is meningism?

Answer 29

Clinical syndrome of headache, neck stiffness and photophobia, often with nausea and vomiting

Question 30

Coma with focal brainstem or lateralising cerebral signs could be due to what?

Answer 30

* Cerebral tumour * Cerebral haemorrhage * Cerebral infarction * Cerebral abscess

Question 31

What investigations can be done to determine the cause of a coma with focal brainstem or lateralising cerebral signs?

Answer 31

* CT or MRI obligatory * If CT/MRI is not diagnostic then investigate as for other causes of coma such as * Metabolic screens * Lumbar puncture * EEG

Question 32

What are some medical causes of coma lasting more than 5 hours?

Answer 32

* 40% due to drug ingestion with or without alcohol * 25% due to hypoxia, could be secondary to MI * 20% due to cerebrovascular event, either haemorrhage or infarction * 15% metabolic, such as diabetes, hepatic failure, renal failure, sepsis, hypercapnia/hypoxia

Question 33

What is the 'locked in' syndrome?

Answer 33

* Condition where patient is aware but has paralysis below the level of the third nerve nuclei, so can open, elevate and depress the eyes but do nothing else and cannot communicate verbally * Diagnosis depends on recognising that the patient can open their eyes voluntarily and signal numerically by eye closure

Question 34

What can occur after coma where the patient is aware but has paralysis below the level of CN III?

Answer 34

Locked in syndrome

Question 35

What does the continuing care of patients in coma include?

Answer 35

* Maintenance of vital functions * Care of skin, avoidance of pressure sores * Attention to bladder and bowel function * Control of seizures * Prophylaxis of DVT, peptic ulceration * Prevention of contractures * Consider the ‘locked in’ syndrome

Question 36

How can a head injury lead to focal neurological signs/epilepsy?

Answer 36

* Diffuse axonal injury * Contusions * Intracerebral haematoma * Extracerebral haematoma * Extradural haematoma * Subdural haematoma

Question 37

What is the difference between an extradural and a subdural haematoma on a CT scan?

Answer 37

Subdural - convex/convex Extradural - concave/convex

Question 38

What is involved in the management of a head injury?

Answer 38

* Stabilise cervical spine * Airway/breathing/circulation * If GCS less than or equal to 8 * Intubation and ventilation * Treat if raised ICP * Cranial imaging * May need decompressive surgery or removal of haematoma * Neuro observation

Question 39

Explain the treatment of raised ICP?

Answer 39

1. Surgery to relieve pressure 1. Haematoma, ventricular shunt 2. Osmotic agents 1. Such as mannitol 3. Nurse with head at 30-45% (venous return) 4. Reduce pain 5. Maintain good PO₂, reduce PCO₂ 6. Reduce metabolism (reduce temperature, barbiturates)

Question 40

What are the clinical features of a non-epileptic attack?

Answer 40

* Sinusoidal tremor, not jerking * Pelvic thrusting * Side to side head movements * Eyes closed and resists opening Partial responsiveness

Question 41

What scale is used to assess stroke and conscious level?

Answer 41

ROSIER (the recognition of stroke in the emergency room)

Question 42

What does ROSIER range from?

Answer 42

-2 to 5

Question 43

How are scores allocated in ROSIER?

Answer 43

* -1 for * Seizure activity * LOC (altered level of consciousness) * +1 for * Face, arm or leg weakness * Speech disturbance or visual field defect

Question 44

A ROSIER score of what predicts stroke?

Answer 44

\>0

Question 45

What is hemicraniectomy?

Answer 45

Is decompressive surgery for severe cerebral swelling post stroke

Question 46

What is a haemorrhagic stroke due to?

Answer 46

Occurs due to hypertensive haemorrhage: * Small perforating arteries in * Brainstem or * Basal ganglia

Question 47

What is consciousness?

Answer 47

The state of being aware and responsive to one’s surroundings

Question 48

What is a vegetative stage?

Answer 48

Absence of responsiveness and awareness due to overwhelming dysfunction of the cerebral hemispheres, with sufficient sparing of the diencephalon and brainstem to preserve autonomic and motor reflexes and sleep/wake cycles