Postural Hypotension Flashcards
Postural Hypotension
When we stand, our bodies should respond to keep our blood pressure the same.
In order for this to happen, 3 things are required:
- normal plasma volume, i.e. the person must not be dehydrated (younger people compensate well for this)
- intact baroreceptors and reflexes
- venomotor tone, the ability of blood vessels to respond to changes in blood flow.
Postural Hypotension
What medications can cause it?
- diuretics
- beta-blockers
- other anti-arrhythmics, antihypertensives and vasodilators
Postural Hypotension
In general, what happens to our blood vessels as we age which could predispose us to postural hypotension?
Poor vascular compliance : seen in ageing blood vessels due to a reduction in elasticity and increased calcification.
Postural Hypotension
Definitions of a ‘significant’ drop in blood pressure:
* Classic
* Initial
* Delayed
* In hypertensive patients
- Classic : reduction of 20/10mmHg within 3 min of standing
- Initial : reduction of 40/20mmHg in first 15 sec – a beat-to-beat recording is required
- Delayed : no agreed definition but occurring >3 min
- In hypertensive patients : reduction of 30mmHg systolic – variability higher in this group
Postural Hypotension
How to measure postural hypotension?
- Ensure that you are able to stand the patient up, getting help beforehand if necessary.
- Use a manual sphygmomanometer, ideally.
- Lie the patient down for 5 min.
- Measure blood pressure.
- Stand the patient up and measure blood pressure in the first minute.
- Repeat at 3 min.
- If blood pressure is still dropping, repeat and keep checking until it resolves.
- Repeat if symptoms change at any point.
Postural Hypotension
Treatment?
(both pharm and non-pharm)
- education / avoidance (getting up slowly / not standing too long / drinking more water)
- preferred medication: Fludrocortisone
- last line medication: Midodrine
Postural Hypotension
How does Fludrocortisone work as a treatment?
acts by expanding blood volume and reducing salt loss
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