Orthostatic Hypotension

Epidemiology

• Very common- around 20% of people over the age of 65 living in the community (this doubles when looking at people in care)

Cause

• It is more common amongst older people for a number of reasons:
  • baroreceptor responses diminish with age
  • long-standing hypertension can also diminish this response; also long-standing vascular disease makes the vessels less likely to respond (less pliable)
    • Elderly patients are also more likely to have an isolated systolic hypertension
      • Whilst this carries a similar cardiovascular risk as generic hypertension, it means that the mean arterial pressure can be significantly low- particularly at the head with gravity
  • cerebral autoregulation is also often poorer in the elderly population
  • elderly patients are also much more likely to be on a number of medications that could cause orthostatic hypotension
• It is important to remember that, like falls, orthostatic hypotension is a symptom which has a cause.  Changes due to aging may be the cause, but others should be looked for.
  • Drugs are the most common cause

  • 

    Drugs that can decrease blood pressure or exacerbate orthostatic hypotension

    NB ALSO ALCOHOL

• Other diseases that cause OH include
  • Diabetes; parkinson’s; addison’s; heart failure; heart valve disorders; GI bleed
• Other causes include dehydration, physical exertion, post-prandial

Definition

• A drop of >20mmHg SBP or >10mmHg DBP between sitting/lying and standing blood pressures (after 3 mins)

Presentation

• Typically patients will report feeling light-headed, dizzy and/or nauseous on standing up (from lying/sitting).  They may or may not fall.  The feeling should resolve after a few minutes (or with returning to sitting/lying position).

Investigations

• Lying/standing blood pressure
• U&Es (hydration status)

Management

• Most commonly- elimination of the causal drug
  • HOWEVER, treatment of hypertension is thought to be beneficial for patients with orthostatic hypotension.  Complete removal of antihypertensive medication is not recommended.
• Correct any underlying causes
• Fluid and salt intake should (usually) be maximised and sleeping with the head raised
• In severe cases which a) do not have an underlying cause and b) cannot be controlled: drug treatment (midodrine (unlicensed) or fludrocortisone) may be used