Clinical stuff Flashcards
(253 cards)
What are the 5 causes of blackouts?
- No blood
- Blood no good
- Brainstem
- Cerebral
- Psychological
What are the causes of “no blood” black outs?
Vasovagal syncope
Postural Hypotension
Hyperventilation
Cardiac Dysrhythmia
What are the causes of “blood no good” blackouts?
Hypoxia
Hypoglycaemia
What is Vasovagal Syncope?
Fainting
What causes Vasovagal snycope?
Vagal activity increaces will symapthetic activity decreses
As a result the heart slows and blood pools in the peripheries.
Cardiac output decreases resulting in inadequate perfusion to the brain.
The patient then collapses, venous return improves and cardiac output goes back to normal
What is postural hypotension?
Patient feels dizzy upon standing, blacks out and collapses
Why does postural hypotension occour?
Decreased symapthetic activity affecting the heart and peripheral circulation
Normal cardio-acceleration and peripheral vasoconstriction in response to standing does not occour.
Cardiac output is no sufficiant resulting in loss of consciousness
What is usually the cause of postural hypotension?
Decreased sympathetic activity due to anti-hypertensive drugs
occasionally due to a physical lesion of the sympathetic pathways
What kind of person experiances postural hypotension
middle aged or elderly
Parkinson’s disease
Peripheral neuropathy
What happens during hyperventilation?
Patients overbeath and wash out CO2 from their blood.
Arterial hypocapnia is a potent cerebral vasocontrictive stimulus.
Inadequate perfusion to the brain resulting in loss of consciousness
How can you prevent hyperventialtion?
Rebreathing into a paper bag.
Stops hypocapnia as you are rebreathing air which has more CO2 in it
What signs and symptoms are suggestive of cardiac dysrhytmia being the cause of blackouts?
- Older patient
- attacks unrelated to posture
- Hx of Ischaemic heart disease
- Palpatations
- Dizziness and colour change prior to collapse
What are Vertebro-basilar transient iscaemic attacks?
Thrombo-embolic material from the heart of proximal large arteries occlude arteries supllying the brainstem.
Cause ischemia of the brainstem tissue untill they are dislodged
what are the symptoms of Vertebro-basilar transient ischaemic attack?
Lasting about 8 minutes
Vertigo
Visual field defects (diplopia, hemianopia)
Auditory phenomena (sudden sensorineural hearing loss)
Facial numbness or paresthesias
Dysphagia, dysarthria, hoarseness
Syncope (drop attacks)
Hemisensory extremity symptoms (eg, contralateral to facial component
What factors make Vertebro-basilar transient ischaemic attacks more likely in a patient?
Older patient
know arteriopathic history
Presence of a source of emboli - MI, atrial fibrilation, neck bruits etc
What is a “hysterical attack”
Some patients attract attention to themselves, at a conscious or unconscious level by having blackouts.
Attacks consist of apparent loss of conciousness with falling and sometimes simulated convulsive movements.
What is narcolepsy?
episodes of sleep of unatural duration and stength occouring at unsual times.
Sufferers may also experiance
- Cataplexy
- Sleep paralysis
- Hypnogogic Hallucintions
What is transient global amensia?
For a few hours the patient acts normally but afterwards they cant remember anything that happened
usually ony happens a couple times in a patients life
What are the layers of the meinges?
Dura mater
Arachnoid mater
Pia mater
What causes Viral Meningitis?
Enteroviruses like ECHO virus
How do you diagnose viral meningitis?
Viral stool culture
Throat swab
CSF PCR
How do you treat viral meningitis?
Supportive - Self limiting
What is the most common cause of community aquired bacterial meningitis in children?
H. influenza
What is the most common cause of community acquired bacterial meningitis in ages 10-21?
Neisseria meningitidis



