CHAPTER 20: The Older Adult
Older Americans now number more than 43 million people and are expected to reach 80 million by 2040, over 20% of the population., Americans are living longer than previous generations: life span at birth is currently 81 years for women and 76 years for men. The population over age 85 years is projected to more than double from 6 million in 2013 to over 14 million in 2040. Hence, the “demographic imperative” to societies worldwide is to maximize not only life span but also “health span,” so that older adults maintain full function as long as possible, enjoying rich and active lives in their homes and communities (Fig. 20-1).
FIGURE 20-1 Enriching the “health span.”
Although statistics group aging by decades, aging is hardly chronologic, measured by time in years, but encompasses a wealth of wisdom and lived experience in addition to the complex interplay of health and illness. The aging population is highly heterogeneous—in disposition, social networks, level of physical activity, and biology. Frailty is one of society’s common myths about aging; more than 95% of Americans older than 65 years live in the community, and only 5% reside in institutional facilities. For those over age 85 years, only 10% live in institutional facilities.
Self-reported health status and functional status supersede disability as measures of healthy aging. In 2009, 76% rated their health as good to excellent, and there has been a decline in the percentage of older adults reporting functional limitations, from 49% in 1990 to 41% in 2010, even though up to 56% report at least one chronic condition. However, recent trends suggest that obesity may increase future levels of disability, especially in African American and Hispanic adults aged 60 to 69 years.
Now, 38% of adults 65 years and above are obese, compared to 22% in the 1988 to 1994 period. Studies show that successful aging is not strictly clinical, but rests on variables such as positive cognition and mental health, physical activity, and social networks. Terminology about aging is in flux. This chapter uses the term “older adult” and at times “senior.” Because evidence about these designations is lacking, take the time to find out which term your patients prefer.
Promoting healthy aging leads to interactive goals in clinical care—“an informed activated patient interacting with a prepared proactive team, resulting in high-quality satisfying encounters and improved outcomes” and a distinct set of clinical attitudes and skills.– Experts recommend “goal-oriented patient care” that is patient-centered, defined as “respectful of and responsive to individual patient preferences, needs, and values, and ensuring that patient values guide all clinical decisions.”
For older adults, this means focusing on the patient’s “individual health goals within or across a variety of dimensions (e.g., symptoms; physical functional status, including mobility; and social and role functions) and determin[ing] how these goals are being met.” This approach individualizes decision-making and allows patients to express preferences about which “health states are important to them and their relative priority,” for example, choosing better symptom control over a longer life span. Goal-oriented care moves beyond “preventive and disease-specific care processes…and condition-specific indicators” like targets for HgA1C or blood pressure.
New paradigms also highlight the importance of shifting assessment to geriatric syndromes that fall outside traditional disease models but are strongly linked to activities of daily living (ADLs). These syndromes are present in almost 50% of older adults. Managing these conditions—cognitive impairment, falls, incontinence, low body mass index (BMI), dizziness, impaired vision and hearing—presents both opportunities and challenges: the focus on healthy or “successful” aging; the need to understand and mobilize family, social, and community supports; the importance of skills directed to functional assessment, “the sixth vital sign”; and the opportunities for promoting the older adult’s long-term health and safety.
The Geriatric Approach for Primary Care
- Learn to quickly identify frail elderly patients; they are most vulnerable to adverse outcomes and most benefit from a holistic geriatric approach.
- Look for common geriatric syndromes, including falls, delirium/cognitive impairment, functional dependence, and urinary incontinence in every patient.
- Learn about efficient assessment tools for geriatrics and geriatric syndromes and teach clinical staff to administer them when possible.
- Be familiar with community resources, such as fall prevention programs, PACE programs, and senior centers.
- Take into account a patient’s goals, life expectancy, and functional status before considering any test or procedure.
- Review advanced directives and goals of care periodically.
- Be knowledgeable about the Beers Criteria (see p. 972) use them to identify potentially inappropriate medications in the elderly and inform periodic comprehensive medication review.
- Adopt an evidence-based approach to health screening, especially in the frail elderly.
- Watch carefully for mood disorders in the frail elderly and consider using geriatric-specific screening tools, such as the five-item Geriatric Depression Scale.
- Provide caregiver support when possible.
Source: Carlson C, Merel SE, Yukawa M. Geriatric syndromes and geriatric assessment for the generalist. Med Clin N Am. 2015:99:263; Adapted from American Geriatrics Society 2012 Beers Criteria Update Expert Panel. American Geriatrics Society updated Beers criteria for potentially inappropriate medication use in older adults. J Am Geriatr Soc. 2012;60:616; and Hoyl MT, Alessi CA, Harker JOet al. Development and testing of a five-item version of the geriatric depression scale. J Am Geriatr Soc. 1999;47:873.
Anatomy and Physiology
Primary aging reflects changes in physiologic reserves over time that are independent of changes from disease. Physiologic changes are especially apt to appear during periods of stress, such as exposure to fluctuating temperatures, dehydration, or even shock. In aging, decreased cutaneous vasoconstriction and sweat production can impair responses to heat; declines in thirst may delay recovery from dehydration; and the physiologic drops in maximum cardiac output, left ventricular filling, and maximum heart rate may impair the response to shock.
At the same time, the aging population displays marked heterogeneity. Investigators have identified vast differences in how people age and have distinguished “usual” aging, with its complex of diseases and impairments, from “optimal” aging. Optimal aging occurs in those people who escape debilitating disease entirely and maintain healthy lives late into their 80s and 90s. Studies of centenarians show that genes account for 20% to 30% of their probability of living to age 100 years. Importantly, healthy lifestyles also account for 20% to 30%., These findings provide evidence for clinicians to promote modifiable lifestyle choices like optimal nutrition, strength training, and exercise and to promote optimal function for older adults that delay the depletion of physiologic reserves and the onset of frailty.
In Western societies, systolic blood pressure tends to rise with aging (Fig. 20-2). The aorta and large arteries stiffen and become atherosclerotic. As the aorta becomes less distensible, a given stroke volume causes a greater rise in systolic blood pressure; systolic hypertension with a widened pulse pressure (PP) often ensues. Diastolic blood pressure (DBP) stops rising at approximately the sixth decade. At the other extreme, many older adults develop orthostatic (postural) hypotension—a sudden drop in blood pressure when rising to a standing position.
FIGURE 20-2 Systolic blood pressure increases with age.
See Table 17-3, Syncope and Similar Disorders, pp. 778–779.
Heart Rate and Rhythm
In older adults, resting heart rate remains unchanged, but there are declines in the pacemaker cells of the sinoatrial node and the maximal heart rate, which affect the response to exercise and physiologic stress. Older adults are more likely to have abnormal heart rhythms such as atrial or ventricular ectopy. Asymptomatic rhythm changes are generally benign. However, some rhythm changes cause syncope, which is a temporary loss of consciousness.
Respiratory Rate and Temperature
Respiratory rate and temperature are unchanged, but changes in temperature regulation lead to a susceptibility to hypothermia.
Skin, Nails, and Hair
With age, the skin wrinkles, becomes lax, and loses turgor. The dermis is less vascular, causing lighter skin to look paler and more opaque. Skin on the backs of the hands and forearms appears thin, fragile, loose, and transparent. There may be purple patches or macules, termed actinic purpura, that fade over time. These spots and patches come from blood that has leaked through poorly supported capillaries and spread within the dermis (Fig. 20-3).
FIGURE 20-3 Skin and hair changes in older adults.
Nails lose luster with age and may yellow and thicken, especially on the toes.
Hair undergoes a series of changes. Scalp hair loses its pigment, changing hair color to gray. Hair loss on the scalp is genetically determined. As early as 20 years, a man’s hairline may start to recede at the temples and then at the vertex. In women, hair loss follows a similar but less severe pattern. In both sexes, the number of scalp hairs decreases in a generalized pattern, and the diameter of each hair gets smaller. There is also normal hair loss elsewhere on the body—the trunk, pubic areas, axillae, and limbs. Women over 55 years may develop coarse facial hairs on the chin and upper lip.
Many of these changes are more common in lighter-skinned patients and may not apply to patients with darker skin tones. For example, Native American men have relatively little facial and body hair compared with lighter-skinned men and should be evaluated according to their own norms.
Head and Neck
Eyes and Visual Acuity
The eyes, ears, and mouth show more visible changes of aging. The fat that surrounds and cushions the eyes within the bony orbit may atrophy, making the eyeballs appear to recede. The skin of the eyelids becomes wrinkled and may hang in looser folds. Fat may push the fascia of the eyelids forward, creating soft bulges, especially in the lower lids and the inner third of the upper lids. Because of fewer lacrimal secretions, older patients may complain of dry eyes. The corneas lose some of their luster.
The pupils become smaller, making it more difficult to examine the ocular fundi. The pupils may also become slightly irregular but should continue to respond to light and show the near reaction (see pp. 235–236).
Visual acuity remains fairly constant between ages 20 and 50 years. It diminishes gradually until approximately 70 years and then more rapidly. Nevertheless, most older adults retain good to adequate vision (20/20 to 20/70 as measured by standard charts). Near vision, however, begins to blur noticeably for virtually everyone. From childhood on, the lens gradually loses its elasticity, with progressive loss of accommodation and the ability to focus on nearby objects. Ensuing presbyopia usually becomes noticeable during the fifth decade.
Aging increases the risk of developing cataracts, glaucoma, and macular degeneration. Thickening and yellowing of the lens impairs the passage of light to the retina, requiring more light for reading and doing fine work. Cataracts affect 10% of patients in their 60s and over 30% in their 80s. Because the lens continues to expand with aging, it may push the iris forward, narrowing the angle between iris and cornea and increasing the risk of narrow-angle glaucoma.
See Chapter 7, Head and Neck, pp. 215–302.
Hearing acuity usually declines with age. Early losses, which start in young adulthood, involve primarily the high-pitched sounds beyond the range of human speech and have relatively little functional significance. Gradually, loss extends to sounds in the middle and lower ranges. When a person fails to hear the higher tones of words but still hears lower tones, words sound distorted and difficult to understand, especially in noisy environments. Hearing loss associated with aging, known as presbycusis, becomes increasingly evident, usually after age 50 years.
Mouth, Teeth, and Lymph Nodes
With aging, there are decreased salivary secretions and loss of taste; medications and various diseases can exacerbate these changes. Decreased olfaction and increased sensitivity to bitterness and saltiness also affect taste. Teeth may wear down, become abraded, or fall out due to dental caries or periodontal disease. In patients without teeth, the lower portion of the face looks small and sunken, with accentuated “purse-string” wrinkles radiating from the mouth. Overclosure of the mouth may lead to maceration of the skin at the corners, or angular cheilitis. The bony ridges of the jaws that once surrounded the tooth sockets are gradually resorbed, especially in the lower jaw.
See Chapter 7, The Head and Neck, pp. 215–302.
With aging, the cervical lymph nodes become less palpable. In contrast, the submandibular glands become easier to feel.
Thorax and Lungs
As people age, they lose lung capacity during exercise. The chest wall becomes stiffer and harder to move, respiratory muscles may weaken, and the lungs lose some of their elastic recoil. Lung mass and the surface area for gas exchange decline, and residual volume increases as the alveoli enlarge. An increase in closing volumes of small airways predisposes to atelectasis and risk of pneumonia. Diaphragmatic strength declines. The speed of breathing out with maximal effort gradually diminishes, and coughing becomes less effective. There is a decrease in arterial pO2, but the O2 saturation normally remains above 90%.
Skeletal changes can accentuate the dorsal curve of the thoracic spine. Osteoporotic vertebral collapse produces kyphosis, which increases the anteroposterior diameter of the chest. However, the resulting “barrel chest” has little effect on function.
A number of changes occur in the neck vessels, cardiac output, heart sounds, and murmurs.
Review the effects of aging on blood pressure and heart rate described on p. 355.
Lengthening and tortuosity of the aorta and its branches occasionally result in kinking or buckling of the carotid artery low in the neck, especially on the right. The resulting pulsatile mass, occurring chiefly in women with hypertension, may be mistaken for a carotid aneurysm—a true dilatation of the artery. A tortuous aorta occasionally raises the pressure in the jugular veins on the left side of the neck by impairing their drainage within the thorax.
In older adults, systolic bruits heard in the middle or upper portions of the carotid arteries indicate stenosis from atherosclerotic plaque. Cervical bruits in younger people are usually innocent.
See discussion of carotid bruits in Chapter 9, pp. 381–382.
Myocardial contraction is less responsive to stimulation from β-adrenergic catecholamines. There is a modest drop in resting heart rate, but a significant drop in the maximum heart rate during exercise. Although heart rate drops, stroke volume increases, so cardiac output is maintained. Diastolic dysfunction arises from decreased early diastolic filling and greater dependence on atrial contraction. There is increased myocardial stiffness, notably in the left ventricle, which also hypertrophies.
Risk of heart failure increases with loss of atrial contraction and onset of atrial fibrillation due to decreased ventricular filling.
Extra Heart Sounds—S3 and S4
A physiologic third heart sound, commonly heard in children and young adults, may persist as late as age 40 years, especially in women. After age 40 years, however, an S3 strongly suggests heart failure from volume overload of the left ventricle in conditions like heart failure and valvular heart disease (e.g., mitral regurgitation). In contrast, a fourth heart sound is seldom heard in young adults other than well-conditioned athletes. An S4can be heard in otherwise healthy older people, but often suggests decreased ventricular compliance and impaired ventricular filling.
See Table 9-8, Extra Heart Sounds in Diastole, p. 407.
Middle-aged and older adults commonly have a systolic aortic murmur. This murmur is detected in approximately one third of people at age 60 years, and in more than half of those reaching 85 years. With aging, fibrotic changes thicken the bases of the aortic cusps. Calcification follows, resulting in audible vibrations. Turbulence produced by blood flow into a dilated aorta may further augment this murmur.
In most older adults, the process of fibrosis and calcification, known as aortic sclerosis, does not impede blood flow. In some, the aortic valve leaflets become calcified and immobile, resulting in aortic stenosis and outflow obstruction. A brisk carotid upstroke can help distinguish aortic sclerosis from aortic stenosis, which has a delayed carotid upstroke, but clinically distinguishing these conditions is difficult. Both carry increased risk for cardiovascular morbidity and mortality.
Similar changes alter the mitral valve, but usually about one decade later than the aortic valve. Calcification of the mitral valve annulus, or valve ring, impedes normal valve closure during systole, causing the systolic murmur of mitral regurgitation. This change in the configuration of the valve may become pathologic as volume overload increases in the left ventricle.