Orthostatic Hypotension in Older and Medically Complex Patients
Orthostatic Hypotension in Older and Medically Complex Patients
Clinicians must remember that most patients with significant OH have either no symptoms or atypical symptoms. Therefore, a negative response to a question like 'do you get dizzy or light-headed when you stand up' is not adequate screening for OH. If OH has been identified or suspected, the history should focus on when the OH symptoms began and under what circumstances the OH was first identified (recent illness, new medications or hospitalization). Although the definition of OH says within 3 min of standing, there are patients who can have initial OH (within 15 s of standing) or delayed OH (beyond 3 min), so a clear description of when the symptoms begin is important. Symptoms associated with bathing and eating should be evaluated. The functional impact of OH and self-treatment measures (such as bending over or squatting) should be queried. Medical and surgical problems, especially as they relate to cardiovascular (hypertension or syncope) and neurological disorders should be reviewed. Prescription medication, nonprescription/dietary supplement use and alcohol use should be reviewed in detail. The dietary history needs to quantify the intake of salt, water and caffeine as well as possible. An autonomic, neurological, cardiovascular and endocrine review of systems should be performed. The autonomic review of systems is useful but nonspecific in older and medically ill patients because many of their symptoms may be related to medications, other medical disorders or surgical procedures. Patients should be asked about changes in sweating, the presence of constipation/diarrhea, urinary difficulties, sexual dysfunction, poor night vision and lack of symptoms associated with hypoglycemia. If the autonomic review of systems is negative, there is not likely to be significant autonomic dysfunction.
A careful BP and pulse determination in multiple positions is a key part of the physical examination. BP can be compared between supine and standing or sitting to standing, although generally a greater difference is seen in the former. Patients are more likely to be orthostatic early rather than later in the day. Meals often lower sitting BP, but postmeal orthostatic responses are not uniformly worse. In some patients with symptoms, excessive tachycardia (>30 beats per min increase) without hypotension is found and referred to as postural tachycardia syndrome. In almost most general clinic settings, it is more important to perform and record the OH BP assessment than to try to optimize when and how it is carried out. A minimal screening OH BP assessment can be a single sitting and 1-min standing BP and pulse. For a more detailed examination, the patient should have 5 min of supine rest and the BP should be taken until it is stable (usually two to three readings). After the person stands, the BP should be measured at 1 and 3 min after standing. OH is diagnosed if there is a 20-mmHg decrease or more in systolic BP, or a 10-mmHg decrease or more in diastolic BP within 3 min of standing. Depending on the history, BP may need to be taken after 5 min of standing, after walking or climbing stairs, and even after prolonged (e.g., 15 min) standing. Similar to hypertension, the diagnosis cannot be made or excluded based on single OH determination. In studies of serial OH determinations, results are variable.
A typical physical examination would include volume assessment by examination of mucus membranes, skin turgor, axillary moistness, jugular venous pressure and peripheral edema. The carotid arteries should be examined for the presence of bruits. Heart sounds should be assessed while the patient is upright because the murmurs of idiopathic hypertrophic cardiomyopathy or mitral valve prolapse may only be audible in the standing position. The neurological examination should focus on evidence of cognitive impairment, depression, Parkinsonism, stroke, cerebellar findings and peripheral neuropathy.
Basic laboratory assessment should include a complete blood count and levels of electrolytes, blood urea nitrogen, creatinine, glucose, albumin, calcium, phosphorus, urinalysis with specific gravity, and ECG. Commonly ordered additional tests include vitamin B12, thyroid-stimulating hormone, echocardiography, cortisol, 24-h urine for volume and sodium (Na). A urine toxicology screen can be ordered if abuse of stimulants or marijuana are suspected. Neuroimaging, peripheral neuropathy evaluation, EEG, sleep studies, carotid ultrasound, 24-h cardiac monitor, exercise stress testing and other testing may also be useful. Tilt testing or 24-h ambulatory BP monitoring can be performed if the symptoms are suspicious for OH, but OH is not demonstrated in the clinical examination. Plasma catecholamines can be checked in the supine position (after 30-min quiet rest) and then again after 10 min standing. These assessments can be helpful in identifying whether the autonomic nervous system response is normal, hypoactive or hyperactive (such as in the case of dehydration). Autonomic function testing and BP response to adrenergic drug infusions can be performed but are generally only performed at specialized centers.
Evaluation
Clinicians must remember that most patients with significant OH have either no symptoms or atypical symptoms. Therefore, a negative response to a question like 'do you get dizzy or light-headed when you stand up' is not adequate screening for OH. If OH has been identified or suspected, the history should focus on when the OH symptoms began and under what circumstances the OH was first identified (recent illness, new medications or hospitalization). Although the definition of OH says within 3 min of standing, there are patients who can have initial OH (within 15 s of standing) or delayed OH (beyond 3 min), so a clear description of when the symptoms begin is important. Symptoms associated with bathing and eating should be evaluated. The functional impact of OH and self-treatment measures (such as bending over or squatting) should be queried. Medical and surgical problems, especially as they relate to cardiovascular (hypertension or syncope) and neurological disorders should be reviewed. Prescription medication, nonprescription/dietary supplement use and alcohol use should be reviewed in detail. The dietary history needs to quantify the intake of salt, water and caffeine as well as possible. An autonomic, neurological, cardiovascular and endocrine review of systems should be performed. The autonomic review of systems is useful but nonspecific in older and medically ill patients because many of their symptoms may be related to medications, other medical disorders or surgical procedures. Patients should be asked about changes in sweating, the presence of constipation/diarrhea, urinary difficulties, sexual dysfunction, poor night vision and lack of symptoms associated with hypoglycemia. If the autonomic review of systems is negative, there is not likely to be significant autonomic dysfunction.
A careful BP and pulse determination in multiple positions is a key part of the physical examination. BP can be compared between supine and standing or sitting to standing, although generally a greater difference is seen in the former. Patients are more likely to be orthostatic early rather than later in the day. Meals often lower sitting BP, but postmeal orthostatic responses are not uniformly worse. In some patients with symptoms, excessive tachycardia (>30 beats per min increase) without hypotension is found and referred to as postural tachycardia syndrome. In almost most general clinic settings, it is more important to perform and record the OH BP assessment than to try to optimize when and how it is carried out. A minimal screening OH BP assessment can be a single sitting and 1-min standing BP and pulse. For a more detailed examination, the patient should have 5 min of supine rest and the BP should be taken until it is stable (usually two to three readings). After the person stands, the BP should be measured at 1 and 3 min after standing. OH is diagnosed if there is a 20-mmHg decrease or more in systolic BP, or a 10-mmHg decrease or more in diastolic BP within 3 min of standing. Depending on the history, BP may need to be taken after 5 min of standing, after walking or climbing stairs, and even after prolonged (e.g., 15 min) standing. Similar to hypertension, the diagnosis cannot be made or excluded based on single OH determination. In studies of serial OH determinations, results are variable.
A typical physical examination would include volume assessment by examination of mucus membranes, skin turgor, axillary moistness, jugular venous pressure and peripheral edema. The carotid arteries should be examined for the presence of bruits. Heart sounds should be assessed while the patient is upright because the murmurs of idiopathic hypertrophic cardiomyopathy or mitral valve prolapse may only be audible in the standing position. The neurological examination should focus on evidence of cognitive impairment, depression, Parkinsonism, stroke, cerebellar findings and peripheral neuropathy.
Basic laboratory assessment should include a complete blood count and levels of electrolytes, blood urea nitrogen, creatinine, glucose, albumin, calcium, phosphorus, urinalysis with specific gravity, and ECG. Commonly ordered additional tests include vitamin B12, thyroid-stimulating hormone, echocardiography, cortisol, 24-h urine for volume and sodium (Na). A urine toxicology screen can be ordered if abuse of stimulants or marijuana are suspected. Neuroimaging, peripheral neuropathy evaluation, EEG, sleep studies, carotid ultrasound, 24-h cardiac monitor, exercise stress testing and other testing may also be useful. Tilt testing or 24-h ambulatory BP monitoring can be performed if the symptoms are suspicious for OH, but OH is not demonstrated in the clinical examination. Plasma catecholamines can be checked in the supine position (after 30-min quiet rest) and then again after 10 min standing. These assessments can be helpful in identifying whether the autonomic nervous system response is normal, hypoactive or hyperactive (such as in the case of dehydration). Autonomic function testing and BP response to adrenergic drug infusions can be performed but are generally only performed at specialized centers.