Postural hypotension

Question 1

Definition of postural hypotension

Answer 1

Drop in systolic BP>20mmHg or diastolic >10mmHg after standing for 3 mins after lying down

Question 2

Causes of postural hypotension

Answer 2

Hypovolaemia (early sign)
Drugs
Addison’s
Hypopituitarism (decreased ACTH)
Autoimmune neuropathy - DM, multisystem atrophy
After a marathon - peripheral resistance is low for a few hours
Idiopathic

Question 3

Which drugs commonly cause postural hypotension?

Answer 3

Nitrates
Diuretics
Antihypertensives
Anti-psychotics

Question 4

How is postural hypotension managed?

Answer 4

Non-pharmacologically

Medication

Question 5

How is postural hypotension managed non-pharmacologically?

Answer 5

Medication review
Lie down when feeling faint
Stand slowly - with escape route (e.g. chair)
Referral to a falls clinic - equipment for monitoring patient under various tilts
Manage autonomic neuropathy (if any)
Increase salt and water ingestion
Physical measures - leg crossing, squatting, elastic compression stockings and careful exercise
If dizziness only post-prandial - eat little and often, and decrease carbohydrate and alcohol intake
Head-up tilt of the bed at night - increases renin release, so that less fluid is lost

Question 6

What medications can be used to manage postural hypotension?

Answer 6

Fludrocortisone - retains fluid - can increase if tolerated
- monitor the patient’s weight
- be careful in patients with heart failure, renal impairment or decreased albumin as this drug can worsen oedema
Sympathomimetics e.g. midodrine or ephedrine