section epub:type=”chapter” id=”c0250″ role=”doc-chapter”> Successful anesthesia care of the older adult population is dependent on the knowledge of the changes of aging and the effects of anesthesia on the older adult patient. This chapter reviews changes in the body due to aging, and provides an overview of the aging mind, and essential concepts for working with an older adult population. Beers list; Cardiovascular risk assessment; Person-centered care; Postoperative delirium The world’s population is aging at a rapid pace. The current population of adults older than 65 years in the United States constitutes 56 million people, or approximately 15% of the population. Projections suggest that, by 2060, 94.7 million individuals will be older than 65 years, or approximately 20% of the population.1 This trend represents two important phenomena: the increase in life expectancy and the aging of the baby boomers (those born between 1946 and 1964) who began to turn 65 in 2011. Older adults are not only living longer but also doing so with improved disease management, resulting in both longer and more independent lives. According to “compression of morbidity theory,” the limit to life span may be stretched significantly with a concurrent delay in the onset of disabling chronic conditions.2 This stretching of the life span would result in a population living longer and healthier than any generation to date. Definitions Activities of Daily Living Daily self-care activities including bathing, eating, dressing, toileting, and grooming. Ageism Stereotyping and discriminating aging individuals or groups on the basis of their age. Aging A lifelong developmental process involving growth, development, and decline. Cognitive Impairment Reduction in mental functioning that results in cognitive changes including short-term memory loss and impaired judgment and thinking. Cultural Competence The ability to provide culturally relevant and appropriate care to persons with diverse values, beliefs, and behaviors. Dementia A loss of brain function that occurs with a certain group of diseases. It affects memory, thinking, language, judgment, and behavior. The most common form of dementia is Alzheimer’s disease. Geriatrics Medical aspect of gerontology in the treatment of acute and chronic conditions in older adults (i.e., a person 65 years of age or older). Gerontologist A professional who is academically trained to apply the scientific study of gerontology to various settings. Gerontology The scientific study of age, aging, and the aged using a life span biopsychosocial approach. Health A state of physical, mental, and social well-being. Individuation of Aging As individuals age, they become more dissimilar to age peers and more rooted in their individual identity. Instrumental Activities of Daily Living The activities performed by people living independently including meal preparation, money management, shopping, and taking medications. Intersectionality The complex, cumulative way in which the effects of multiple forms of discrimination (such as ageism, racism, sexism, and classism) combine, overlap, or intersect, especially in the experiences of marginalized individuals or groups. Person-Centered Care Focuses on individual care needs by understanding how the individual experiences his or her situation to most effectively address needs and desired outcomes. Presbycusis Age-associated hearing changes, particularly sensitive to lifestyle, resulting in reduction in ability to hear high- and low-frequency sounds. Presbyopia Age-associated visual changes of diminished ability to focus on near objects, accommodation to changes between light and dark, and contrast in environment and print material (print and background). Senescence Physiologic aging process that involves growth, maintenance, and decline. Varies by individual, by organ system, and by genetic, environmental, and phenotypic characteristics. Social Determinants of Health Conditions in the places where people live, learn, work, and play that affect a wide range of health and quality-of-life-risks and outcomes. The World Health Organization defines health as a state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity.3 In this view, older adults may then perceive themselves as healthy despite physical limitations or disease. It is essential in caring for the older patient to recognize overall health from physiologic, psychological, social, and even spiritual perspectives. In assessing an older adult’s health, an appropriate delineation is between an individual’s chronologic age versus functional age. Some individuals who are more judicious in using preventive health measures and who maintain more active lifestyles may have little decline or age-related comorbidities, reflecting greater functioning relative to chronologic age, whereas others may have multiple comorbidities, perhaps at an even earlier age, reflecting functional limitations relative to age. Although labeling based on chronologic age is swiftly decreasing in popularity, gerontologists have made the distinctions among young-old (65–75), old-old (75–85), and oldest-old (85 +, the fastest growing age group) to differentiate individuals included in the broader category of “older adults” or elders. In addition, the term centenarians, a rapidly increasing age segment, refers to individuals over the age of 100. In terms of functional capacity, gerontologists also describe aging in terms of primary, secondary, and tertiary aging.4 Primary aging represents aging free of disability and disease. Secondary aging encompasses developmental changes affected by lifestyle, disease, or factors that are not inevitable processes of biological aging. Tertiary aging is rapid loss and decline experienced at the end of life. It is essential that we continue to differentiate between chronologic age and functional status both in terms of clinical significance of effectively meeting the needs of elders as patients and by way of raising awareness of the enormous diversity and heterogeneity of our growing elder population. Many different chronologic markers are used for governmental determinations and legal purposes (i.e., 40 years of age for age discrimination determination, 50 years of age for AARP membership, and 65-plus years of age for Social Security). As a result, no one definition of old age or older adult is accepted. Because no biomarkers exist, a definition of when old age begins is difficult because individuals age at different rates than is reflected simply by chronologic age. The growing complexity and diversity of the aging population mandate a holistic interprofessional biopsychosocial approach to care to move beyond a simplistic chronologic marker of age toward a more accurate functional assessment—this is the hallmark of a gerontological person-centered approach. Care of the older adult patient is particularly important in the postanesthesia care unit because of the normal physiologic changes that occur with aging and may be compounded by multiple comorbid conditions. With advancing age, the potential risks of complications from surgical procedures increase because of the potential for multiple comorbidities. Morbidity and mortality are at least fourfold more likely in older adults and tenfold more likely in emergency procedures.5 These conditions include congestive heart failure, insufficient oxygenation of the blood, improper elimination of carbon dioxide, fluid and electrolyte imbalance, diabetes and the associated complications, and drug toxicity. Advances in anesthetic care, including the use of comprehensive geriatric assessment, have resulted in a substantial reduction in perioperative morbidity and mortality in the aging population.6 Successful anesthesia care of the older adult patient is highly dependent on the knowledge of the changes associated with aging and the effects of anesthesia on the older patient. Therefore, the focus of this chapter is primarily on the normal aging changes that take place in addition to the disease states associated with aging and their translation to functional status, especially of the cardiovascular system. It is essential to keep in mind throughout this chapter that the rate at which each individual and organ system ages is highly individualistic—hence the need for a person-centered approach. This phenomenon is referred to as the individuation of aging.7 Individual genes, hormonal balance, diet, medications, environmental exposure, and emotional stress and burden are all factors that influence individual biological aging. Cardiovascular health is essential to the overall well-being of the older adult. Healthy cardiovascular functioning can be maintained across the life span, and disease can be prevented through healthy lifestyle choices and preventive care (primary aging); however, heart disease remains the leading cause of death for both males and females (secondary and tertiary aging).8 Of all of the body systems, the cardiovascular system exerts the most influence on anesthesia and general health outcomes.8 Annually, more than 1 million surgeries are complicated by adverse cardiac outcomes such as postsurgical myocardial infarction or death from cardiac disease.9 This risk can be reduced with a thorough preoperative interview and assessment that examines functional capacity and existing comorbidities and the current treatment regime.8 The assessment of functional capacity reflects the ability to perform activities of daily living (ADLs) that require sustained aerobic metabolism.10 Biomarkers of aging, including aerobic capacity, are currently the best predictors of quality of biologic age. Exercise tolerance is also one of the most important predictors of perioperative outcomes in older adult patients.11,12 Poor exercise tolerance reflects low functional capacity and greater severity of disease. Functional status is usually reflected in metabolic equivalent (MET) levels. One MET corresponds to a resting oxygen consumption of 3.5 mL/kg/min. MET scores are multiples of resting metabolism, which are used as a point of reference to describe the oxygen demands of any activity.13Box 50.1 provides examples of MET ratings of activities. Functional status can be ascertained during the preoperative screening. Questions addressing ADLs and assessing lifestyle habits, such as housecleaning, vacuuming, walking, stair climbing, and any participation in regular exercise, should provide adequate information for a subjective assessment of the patient’s functional status.14,15 Objective assessment can be made via exercise testing. Patients unable to regularly meet a 4-MET demand have an increased perioperative cardiac risk.16 There are several structural changes frequently seen with advancing or older age that occur within the cardiovascular system. Changes of the arteries include dilation of the large arteries accompanied by thickening of the arterial walls and changes in wall matrix. An increase in elastin and collagen tissues in the heart and arteries can cause arterial wall thickening and an increase in smooth muscle tone.16–19 Increased vascular stiffness leads to elevated systolic arterial pressure and pulse wave velocity, early reflected pulse pressure waves, and late peak systolic pressure, which trigger a series of cardiac adjustments. A resultant augmenting of aortic impedance and cardiac mechanical load may be seen. Clinically elevated left ventricular afterload causes an increase in myocyte size and thickening of the left ventricular wall.18 When combined with augmentation of aortic impedance, elevated afterload prolongs myocardial contraction. This adaptive measure preserves cardiac function by lengthening the amount of time available for the heart to eject blood into stiffened vasculature. The resultant prolonged myocardial contraction delays ventricular relaxation time, which manifests as a decrease in early ventricular filling.19–23 With advancing age, the cardiovascular system undergoes important changes. Thickening and stiffening of the large arteries develop, which cause systolic blood pressure to rise and diastolic blood pressure to decline after the sixth decade.24 Left ventricular systolic function is maintained across the life span, and early diastolic filling rate declines 30% to 50% between the third and ninth decades.24 With aging, alterations in calcium release from the myoplasm to the sarcoplasmic reticulum may contribute to the changes in early diastolic filling.16,23 For maintenance of stroke volume, end-diastolic filling is increased.16 The effectiveness of this strategy is dependent on the atrial contribution to end-diastolic filling; therefore, left atrial size increases.20 Enlargement of the atria raises the likelihood of atrial fibrillation among elders, thus underscoring the importance of stable hemodynamics to ensure normal sinus rhythm. Gender differences may be found in certain age-related changes in cardiac function.16 Men seem to have different compensatory mechanisms compared with women. To maintain stroke volume in the presence of the age-associated decrease in heart rate, men have an increase in left ventricular end-systolic volume and left ventricular end-diastolic volume. This mechanism preserves cardiac output in aging men, whereas a 15% decrease is seen in cardiac output in women. Table 50.1 summarizes cardiac changes in response to exercise that occur with age.25 LV, Left ventricular; SVR, systemic vascular resistance ↔, no change; ↑, increase; ↓, decrease. Adapted from Eagle KA. Perioperative cardiac assessment for noncardiac surgery: eight steps to the best possible outcome. Circulation. 2003;107:2771–2774. The most clinically relevant age-related changes in cardiovascular function are increased myocardial stiffness and all of the subsequent compensatory actions and blunted beta-adrenergic responses. During increased oxygen demand, the most relevant changes in the older patient are autonomic reflex dysfunction and beta-adrenoreceptor responsiveness. See Table 50.1 for cardiovascular age-related changes to upright peak exercise. Preoperative risk assessment is an important component in minimizing perioperative morbidity and mortality. This assessment is best achieved through the work of an interdisciplinary team that includes the patient, the primary care physician, the surgeon, and the anesthesia professional among others. In addition, training and expertise are essential to the quality care of older adult patients. It must not be assumed that gerontological training is implicit among members of the health care team. To ensure quality care, gerontological training is essential. This assessment relies on the evaluation of the interaction of clinical markers, functional capacity, type of surgical procedure, and age. When risks are identified, measures should be used to minimize the risks before surgery and to improve immediate periprocedural outcomes and long-term clinical outcomes. Some clinical markers act as predictors of perioperative cardiovascular risk. These markers can be categorized by the perioperative risk associated with them (Box 50.2) as major, intermediate, and minor perioperative risk.11 In addition, the type of surgery coupled with the degree of hemodynamic stress incurred during the surgery are the major determining factors of perioperative risk.11,12 Emergency surgeries are particularly high risk, especially in older patients. Other high-risk surgeries include vascular, cardiac, abdominal, and thoracic surgeries.26Box 50.3 categorizes surgery-specific risk according to the incidence rate of cardiac death and nonfatal myocardial infarction for noncardiac surgical procedures.
50: Care of the Older Patient
Abstract
Keywords
The aging body: an overview
Cardiovascular System
Functional Capacity
Structural Changes
Cardiovascular Physiology
Peak Response at Age 20 Years
Change in Peak Response Between 20 and 80 Years
LV end-diastolic volume
↔, ↓
↑ 30% males; ↔ females
LV end-systolic volume
↓
↓ 100%
Ejection fraction
↑
↓ 15%
Stroke volume
↑
↔
Heart rate
↑
↓ 25%
Cardiac output
↑
↓ 25%
Stroke work
↑
↑ 15% males; ↔ females
SVR
↓
↑ 30%
Oxygen consumption
↑
↑ 50%
Plasma catecholamines
↑
↑
Myocardial contractility
↑
↓ 60%
Beta-adrenergic stimulation
Fully functional
↓
Cardiovascular Risk Assessment
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