Journal of Gerontological Nursing

The Prevalence of Orthostatic Hypotension in high-risk ambulatory elders

Mary Walczak, RN, MSN

Abstract

Inactivity, underlying medical illness, medications, and even food ingestion may contribute to the prevalence of orthostatic hypotension.

Abstract

Inactivity, underlying medical illness, medications, and even food ingestion may contribute to the prevalence of orthostatic hypotension.

Hypertension has been widely recognized by the medical community as a contributor to heart attacks, strokes, and kidney disease (New York Times Magazine. June 19, 1988:50-52). However, orthostatic hypotension (OHX or postural hypotension, is less recognized yet may be as serious a threat, especially in elders.

Most research on orthostatic hypotension in the elderly has been conducted on healthy individuals without known risk factors of diabetes, arteriosclerotic heart disease (ASHD), or antihypertensive medications.1 Prevalence has ranged from 6% to 68%. 1,2 Seventy-four older adults attending a day center for the elderly were evaluated. This article explores the etiology, prevalence at the center, and nursing management of patients with orthostatic hypotension.

DEFINITION

Orthostatic changes in blood pressure may be systolic (a fall of 20 mm Hg or more in systolic blood pressure), or diastolic (a fall of 10 mm Hg or more in diastolic blood pressure), narrowing of pulse pressure (a fall in pulse pressure of 18 mm Hg or less), or tachycardia (a rise of 28 beats or more, or at least 10 beats per minute during at least 3 minutes of standing).3 For the purpose of this study, orthostatic hypotension was defined as a fall of more than 20 mm Hg in systolic pressure or more than 10 mm Hg in diastolic pressure. Pulse pressure readings were not considered in this study.

BACKGROUND

Orthostatic intolerance is often characterized by dizziness or lightheadedness, blurring of vision and fatigue followed by confusion, and impending or actual syncope when rising from a supine or sitting position.4,5 The consequences of these events may be disabling, including institutionalization. Physiological changes of aging superimposed on illness or the use of medications appear to contribute to the prevalence of orthostatic hypotension and its symptoms.6 It is the combination of known risk factors of debility, medications, and common geriatric illnesses, such as diabetes, that notably create the symptoms.7-9

Normally, cardiac output is maintained through stimulation of the baroreceptors in the carotid sinus and the aortic arch, thereby creating vasoconstriction and tachycardia in response to falling arterial pressure as one stands.9,10 The baroreceptor reflex is intact in elders, but it is often blunted.4 Increased sympathetic activity and suppression of parasympathetic performance increases release of catecholamine, renin, angiotensin, and aldosterone to restore normal blood pressure.9,10 Orthostatic hypotension can result from failure of any of these mechanisms to adapt to postural change.

At least three hormonal influences have also been attributed to the regulation of arterial pressure. The norepinephrine, along with the epinephrine, vasoconstrictor mechanism causes essentially the same effects on the circulatory system as direct sympathetic stimulation. The vasoconstructive effects of renin-angiotensin and vasopressin mechanisms provide a rapid or moderately active control of arterial pressure.9-11

ASSOCIATED RISK FACTORS

Inactivity, underlying medical illness, medications, and even food ingestion may contribute to the prevalence of orthostatic hypotension.912 Medications should always be considered first as the major causative agent in any nonspecific complaint of an elder, including postural hypotension.

Many medications such as diuretics, antihypertensives, major tranquilizers, and antidepressants can lead to an orthostatic fall in blood pressure and produce symptoms of dizziness.9,13 Food ingestion may also influence blood pressure changes.

Healthy and frail individuals were observed to have a 15 mm Hg decline in systolic blood pressure within a half hour of eating.12 Diseases such as diabetes mellitus and ASHD are more common in elders and increase one's risk of developing orthostatic hypotension (New York Times Magazine. June 19, 1988:50-52).5

The peripheral neuropathy associated with diabetes can interfere with sympathetic vasoconstriction activity, thereby contributing to orthostatic hypotension. Diabetes mellitus damages the autonomic pathways, which contribute to compensatory changes in heart rate. In me presence of occluded cerebral or coronary arteries, any additional cause for reduced blood flow could result in a cerebral vascular accident.11,13

A well-known but poorly understood contribution to dementia is that associated with multiple cerebral infarcts, which interrupt the pathways of memory, language, perception, and personality. It is noteworthy that aging, hypertension, and diabetes are shared risk factors of orthostatic hypotension and multi-infarct dementia. It has been hypothesized that the combination of ASHD and OH may contribute to multiinfarct dementia (New York Times Magazine. June 19, 1988:50-52). It becomes evident, therefore, that symptoms result from the combination of risk factors and the evidence of orthostatic hypotension.

Table

TABLE 1PREVALENCE OF ORTHOSTATIC HYPOTENSION IN ELDERLY AT A DAY CENTER WITH KNOWN RISK FACTORS

TABLE 1

PREVALENCE OF ORTHOSTATIC HYPOTENSION IN ELDERLY AT A DAY CENTER WITH KNOWN RISK FACTORS

Table

TABLE 2PREVALENCE OF CONTRIBUTING RISK FACTORS OF ELDERS WITH ORTHOSTATIC HYPOTENSION*

TABLE 2

PREVALENCE OF CONTRIBUTING RISK FACTORS OF ELDERS WITH ORTHOSTATIC HYPOTENSION*

METHOD

Seventy-four unselected clients attending the day center between the ages of 63 and 93 were evaluated for the presence of orthostatic hypotension. Guidelines for taking blood pressures were reviewed with each of the data collectors. Blood pressures were taken using the same sphygmomanometer and cuff. Readings were taken 20 minutes after the participant was lying down, and 2 minutes after standing unsupported. The diaphragm of the stethoscope was used occluding the right brachial artery.

There were no excessively obese elders participating in this study. Erroneously high arterial blood pressure values are obtained in very obese individuals because of the excessive girth of me upper arm. Valid recordings under these circumstances would have required the use of a broad cuff.

Subjects were informed of the purpose of the study and verbal permission was obtained for participation in the study. Prior to the study, an explanation of the activity was offered to each participant.

RESULTS

Twenty-one, or 28%, of those individuals studied showed evidence of OH. This was evidenced by changes in systolic, diastolic, or a combination of systolic and diastolic measurements (Table 1 ). Table 2 illustrates the prevalence of contributing risk factors in elders with OH. Eighty-one percent of those individuals tested had risk factors known to contribute to OH.

Eighty-five percent of those studied were women, and 15% were men. One third were between the ages of 63 and 69, one third were between 70 and 79, 24% between 80 and 89, and the remainder between 90 and 93. It is of note that no women demonstrated evidence of diastolic hypotension. Additional research in this area is needed.

Twenty-nine percent of those with systolic changes, 83% of those with diastolic changes, and none of the patients with both systolic and diastolic blood pressure changes offered complaints of feeling dizzy or lightheaded on rising from a supine to a standing position. This was addressed because patients who complain of dizziness or lightheadedness do not always show a characteristic drop in blood pressure.

NURSING MANAGEMENT AND EDUCATION

Management of patients with OH necessitates that nursing interventions be aimed at preventing injuries from associated falls. Nurses who identify individuals experiencing symptoms in combination with OH should direct those individuals to assume a supine position until symptoms abate. The same persons should be encouraged to arise slowly and sit at the edge of a bed or examination table before standing.

Gradual changes in position stimulate release of renin, which prevents a precipitous drop in blood pressure.

Patients should also be encouraged to sleep with a 15° (approximately 10 in) head elevation to reduce nocturnal hypertension, thereby mimicking orthostatic influences on the kidneys. Raising the head lowers renal arterial pressure, thereby encouraging sodium and water retention through stimulation of the renin angiotensin system.

Elastic stockings should be donned before getting out of bed. Wearing such stockings reduces venous pooling in the legs. This venous pooling results in decreased cardiac output and arterial pressure.13

Postprandial hypotension may occur up to 1 hour following a meal. The etiology is speculative, however. Suggestions of splanchnic blood pooling and inadequate baroreflex response during digestion are both plausible explanations.13 Patients should be encouraged to minimize their activity following eating. Diets including a low sodium content would be prudent because this sodium may cause hypovolemia.

Hot baths should be avoided because they raise body temperature, dilating blood vessels and causing venous pooling. Elders should be encouraged to arise from the bath slowly. Assistive devices, such as shower seats and hand rail bars, should be installed to minimize potential injuries.

DISCUSSION

Although nurses cannot reverse the alterations in function of the autonomic nervous system associated with aging or prevent the onset of ASHD or diabetes, much can be done to reduce their associated symptoms and threat of synergistic effects on blood pressure. Careful measurements of blood pressures and pulses in various positions should be incorporated into routine nursing practice.

Individuals with OH must be identified and nursing interventions implemented to reduce the potential for injury related to falling from OH. Older adults may have evidence of postural changes, which can result in syncope that can be permanently disabling, greatly affecting their quality of life.

A compensatory increase in heart rate occurs with OH secondary to volume depletion. Failure of the heart rate to increase in a patient with OH may indicate a dysfunction of the autonomic nervous system.13 Although the influence of heart rates were not evaluated in this study, future studies in this area would be of academic interest and clinical significance. Controlled studies are also needed to evaluate the individual contributions of various risk factors on postural blood pressure.

REFERENCES

  • 1. Mader SL, Josephson KR. Rubenstein LZ. JAMA. 1987;258:1511-1514.
  • 2. Weiner WJ, Nora LM, Glantz RH. Elderly inpatients: Postural reflex impairment. Neurology. 1984; 34:945-950.
  • 3. Streuen DHP. Orthostatic disorders: Mechanisms, manifestations and treatment. Plenum. 1987;6:111-112.
  • 4. Matteson MA, McConnel ES. Gerontological Nursing: Concepts and Practice- Philadelphia: WB Saunders Co; 1988.
  • 5. Miller JW, Streiten DHP. Vascular responsiveness to norepinephrine in sympathicatonic orthostatic intolerance. J Lab Clin Med. 1990;115:549-558.
  • 6. Vargas E. Cardiovascular Mechanisms in the Elderly. England: University of Manchester; 1983. Thesis.
  • 7. Holtzman D. Moves toward hypotension fall. Insight. 1988; July 18:56-57.
  • 8. Robbins A, Rubenstein L. Postural hypotension in the elderly. J Am Geriatr Soc. 1984; 32:769-774.
  • 9. Rosenthal MD, Naliboff B. Postural hypotension: Its meaning and management in the elderly. Geriatrics. 1988; 43(12):3l-42.
  • 10. Guyton AC. Textbook of Medical Physiology. 5th ed. Philadelphia: WB Saunders Co; 1976.
  • 1 1 . White NJ. Heart rate changes standing in the elderly patients with orthostatic hypotension. Clin Sci. 1980; 58:41 1-413.
  • 12. Lipsitz LA, Nyguist RP, Wei JY, et al. Postprandial reduction in blood pressure in the elderly. N Engl J Med. 1983;309:81-86.
  • 13. Whall AL. The psychoactive properties of commonly prescribed drugs. Journal of Gerontological Nursing. 1 988; 14( 1 1 ):3 1 -32.

TABLE 1

PREVALENCE OF ORTHOSTATIC HYPOTENSION IN ELDERLY AT A DAY CENTER WITH KNOWN RISK FACTORS

TABLE 2

PREVALENCE OF CONTRIBUTING RISK FACTORS OF ELDERS WITH ORTHOSTATIC HYPOTENSION*

10.3928/0098-9134-19911101-07

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