Blackout (oxford clin cases)

Question 1

What is the difference between syncope and loss of conciousness?

Answer 1

Syncope is loss of consciousness that specifically results from hypoperfusion of the brain

Question 2

What are some causes of syncope? Explain how they cause it

Answer 2

Cardiac- the heart does not pump enough blood to adequately perfuse the brain
Reflex- there is a reflex that causes mammals to ‘play dead’, this involves slowing of the heart rate and reduction in blood pressure
Orthostatic- when we get up from lying down there needs to be vasoconstriction to prevent a fall in blood pressure, because this takes a while in the meantime the heart rate rises to compensate, if someone is dehydrated etc perfusion is not adequate
Cerebrovascular- other causes eg narrowing of a blood vessel on the way from the heart to the brain (unocommon)

Question 3

What are some syncopal causes of loss of consciousness?

Answer 3

Vasovagal spasm
Cardiac arrythmia
Drugs
Dehydration

Question 4

What are some non-syncopal causes of loss of consciousness?

Answer 4

Intoxication
Head trauma
Metabolic
Psychogenic seizure

Question 5

What is a psychogenic seizure

Answer 5

When someone thinks they lost consciousness but they didn’t

Question 6

What is vasovagal syncope?

Answer 6

When the body has an overreaction to a stimulus/ is triggered resulting in a drop in blood pressure and reduction in heart rate, leading to hypoperfusion of the brain

Question 7

What is the most common cause of blackout in someone who is young?

Answer 7

Vasovagal syncope

Question 8

What is the most common cause of blackout in someone who is middle aged?

Answer 8

Vasovagal syncope

Cardiac arrythmia

Question 9

What is the most common cause of blackout in someone who is old?

Answer 9

Orthostatic hypotension caused by medications

Question 10

What drugs cause orthostatic hypotension?

Answer 10

ACE inhibitors
Beta blockers
Alpha blockers
Calcium channel blockers

ie drugs that slow the heart rate/ would be given for hypertension which is commoner in older people

Question 11

What story will patients who blackout due to vasovagal syncope give when they describe the blackout?

Answer 11

They will say they felt it coming ie they felt themselves go clammy/ pale, were dizzy, had a feeling in their stomach and knew they were going to loose consciousness

Question 12

If there was no warning before the blackout, what is the most likely cause?

Answer 12

Cardiac arrhythmia

Question 13

If the patient stood up before the blackout, what is the most likely cause?

Answer 13

Orthostatic hypotension

Question 14

If there were precipitating factors before the blackout eg fear/pain, what is the most likely cause?

Answer 14

Vasovagal syncope

Question 15

If a patient was sitting or lying down when they blacked out, what is the most likely cause?

Answer 15

Cardiac arrythmia

Question 16

If the patient was exercising when they blacked out, what is the most likely cause?

Answer 16

Cardiac pathology

Question 17

What cause of blackout should you always ask about you that can take a few days to have an effect?

Answer 17

Head trauma eg subdural haemorrhage

Question 18

What may happen during the episode of blackout that indicates epileptic seizure?

Answer 18

Moving their limbs

Biting their tongue

Question 19

What may happen during the episode of blackout that indicates vasovagal syncope?

Answer 19

Twitching and incontinence