Blackout

Question 1

Categorise the causes of blackout

Answer 1

1. Syncope
   a. Reflex
   b. Cardiac
   c. Orthostatic
   d. Cerebral
2. Non syncopal

Question 2

Why does it matter whether a patient had a warning before a blackout

Answer 2

No warning suggests cardiac cause (e.g. arrhythmia, aortic stenosis) or more rarely a cerebrovascular cause

Other types of blackouts usually have a warning e.g. aura preceding epileptic seizure, dizziness preceding a vasovagal episode

Question 3

T/F Insulin as well as other drugs which increase the sensitivity of tissues to insulin can lead to blackouts

Answer 3

F. Insulin can make patients to susceptible to hypoglycemia, but this is NOT the case for medications that act by increasing sensitivity to, rather than the production of, insulin (such as metformin etc.)

Question 4

Why can anti-arrhythmics be assocaited with blackout

Answer 4

Because they paradoxically predispose to arrythmia… meaning they put you at risk of syncope

Question 5

Why is warfarin important to ask about in blackout history

Answer 5

Puts one at increased risk of subdural haemorrhage, and threshold for requesting CT head is lower if they are taking these drugs

Question 6

Which recreational drugs could be assocaited with blackout

Answer 6

STIMULANTS… cocaine and amphetamines stimulate the heart causing tachyarrythmias and possibly a drop in cardiac outpout

Question 7

T/F the loudness of a carotid artery bruits has no relation to the severity of stenosis

Answer 7

T!

Question 8

What blood pressure change would indicate an orthostatic hypotension

Answer 8

Take the blood pressure lying down and within 2 minutes of standing. Orthostatic hypotension is defi ned as a drop of ≥20 mmHg in systolic blood pressure or ≥10 mmHg diastolic on standing.