Postural hypotension Flashcards
Define postural hypotensions
drop in systolic pressure upon standing.
The drop should be greater than 20 mmHg
What are the presenting complaints of postural hypotension
- blackout
- dizziness
- light headed
- ## blurred vision
as a result of impaired cerebral perfusion
What are the causes of postural hypotension?
1) Venous pooling of blood
- varicose veins
- prolonged standing
2) hypovolaemia
- dehydration
- haemorrhage (GI bleed)
3) Drugs:
- antihypertensive
- diuretic
- vasodilator
- tranquilisers
drugs that affect reflex control of BP:
- levodopa
- antidepressants
4) Addisonian disease:
- addison’s (low steroids)
- hypopituitarism
5) impaired vasomotor tone
- diabetic autonomic neuropathy
6) reduced muscle tone
(prolonged bed rest)
What factors influence the symptoms of postural hypotension (dizziness, blackouts)
speed of position change
coughing
What does lack of sweating indicate in postural hypotension/
neurogenic cause
What invx should be done for postural hypotension?
- blood glucose
- U+Es
- check urine for proteinuria (may be secondary to systemic amyloidosis)
What conditions are associated with postural hypotension?
Cardiac:
- aortic stenosi
- arrhythmias
- MI
- heart failure
- constrictive pericarditis
Haematological:
- pernicious anaemia
Endocrine:
- Diabetes
Neuro:
- vasovagal faints
- alcoholic neuropathy
- Parkinson’s disease
- vasospasm
Other:
pregnancy
varicose veins
What is the treatment for postural hypotension?
- avoid triggers (positions, food, drugs, high temp, )
- medication review
- stand slowly
- morning caffiene
- raise head of bed
- compression socks
- increase fluid volume (raise salt intake, fludrocortisone, alpha receptor agonist)
What are the differentials for blackouts?
- Postural hypotension
- TIA
- cardiogenic syncope (e.g. with arrhythmia)
- epilepsy
- hypoglycaemia
