From the Guidelines
Orthostatic hypotension in a geriatric male is most likely caused by age-related changes in baroreceptor sensitivity, autonomic dysfunction, and reduced vascular compliance, which impair the body's ability to maintain blood pressure during positional changes, as supported by the 2018 ESC guidelines for the diagnosis and management of syncope 1.
Pathophysiology of Orthostatic Hypotension
The pathophysiology of orthostatic hypotension involves a complex interplay of factors, including:
- Impaired increase in total peripheral resistance and heart rate in autonomic failure, resulting in pooling of blood 1
- Severe volume depletion, which can be exacerbated by medications such as diuretics and alpha-blockers 1
- Age-related changes in baroreceptor sensitivity and reduced vascular compliance, which impair the body's ability to maintain blood pressure during positional changes 1
Clinical Presentation
The clinical presentation of orthostatic hypotension can vary widely among patients, and symptoms depend more on the absolute blood pressure level than the magnitude of the fall 1. Common symptoms include:
- Dizziness and light-headedness
- Fatigue and weakness
- Visual and hearing disturbances
- Low back pain, neck or precordial pain
Diagnosis
Diagnosis of orthostatic hypotension is based on a sustained decrease in systolic blood pressure >20 mmHg, diastolic blood pressure >10 mmHg, or a sustained decrease in systolic blood pressure to an absolute value <90 mmHg within 3 minutes of active standing or head-up tilt of at least 60 degrees 1.
Management
Management of orthostatic hypotension should focus on non-pharmacological approaches, including:
- Slow position changes
- Adequate hydration (1.5-2 liters of fluid daily)
- Salt intake of 6-10 grams per day (unless contraindicated by heart failure or kidney disease)
- Compression stockings
- Avoiding alcohol and large meals
- Reviewing and potentially adjusting medications that may contribute to hypotension, particularly antihypertensives, diuretics, alpha-blockers, and certain psychiatric medications 1 If symptoms persist, pharmacological treatment may include fludrocortisone or midodrine, which require monitoring for supine hypertension, electrolyte imbalances, and fluid retention 1. Regular follow-up is essential to assess treatment efficacy and monitor for adverse effects.
From the Research
Causes of Orthostatic Hypotension
- Orthostatic hypotension is very common in the elderly, with a prevalence of 10-30% in the elderly population 2
- Aging coupled with diseases such as diabetes and Parkinson's disease can result in baroreflex failure, leading to orthostatic hypotension 2
- Non-neurogenic causes, such as medications, are the most common cause of orthostatic hypotension in the elderly 3
- Medications such as antihypertensives, tricyclic antidepressants, diuretics, and vasodilators can induce hypotensive effects and influence the blood pressure response to orthostatism 3, 4
- Other causes of orthostatic hypotension include hypovolemia, primary autonomic disorders, secondary autonomic disorders, and vasovagal syncope 5
Pathophysiology of Orthostatic Hypotension
- Orthostatic hypotension occurs when mechanisms for the regulation of orthostatic blood pressure control fail 2
- The fall in blood pressure seen in orthostatic hypotension results from the inability of the autonomic nervous system to adequately compensate for the 500 mL blood that is estimated to pool in the lower extremities on assuming an upright posture 5
- The decrease in venous return results in a concomitant decrease in cardiac output and thus hypoperfusion of the cerebral circulation, possibly resulting in syncope or various other symptoms 5
Risk Factors for Orthostatic Hypotension
- Advanced age is a significant risk factor for orthostatic hypotension, with the prevalence increasing exponentially in the geriatric population 6
- Polypharmacy and the use of certain medication classes, such as diuretics and vasodilators, can increase the risk of orthostatic hypotension 4
- Underlying medical conditions, such as diabetes and Parkinson's disease, can also increase the risk of orthostatic hypotension 2