The Elder Patient

Published on 08/04/2015 by admin

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Last modified 08/04/2015

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Chapter 182

The Elder Patient

Perspective

The population of the United States is aging, with the proportion of people older than 65 years increasing at twice the rate of younger people. In 2010, 13% of the population was older than 65 years, and by 2045 one in five people are expected to be older than that age.1 In 2008 the first baby boomer turned 62 years old, and as of January 2011 this so-called silver tsunami began to qualify for Medicare.

These changing demographics affect the practice of emergency medicine. In 2008 elders accounted for 46% of the 123 million emergency department (ED) visits, and ED visits in this age group are increasing by one third every 10 years.2 Elders presenting to the ED are more likely to arrive by ambulance, to have a more emergent condition than younger patients, and to require longer evaluations.3 One third of these patients are admitted, many to the intensive care unit.4 As the number of ED visits by elders continues to climb, the health care impact will be enormous.

Principles of Disease

Physiologic Changes of Aging

Physiologic changes of aging affect virtually every organ system and have many effects on the health and functional status of elders (Table 182-1). Heart disease is the leading cause of hospitalization and death.5 Increased peripheral vascular resistance with aging leads to an increased risk of hypertension. Decreased inotropic and chronotropic cardiac functioning compromises the patient’s ability to respond to physiologic stressors. Atherosclerosis is common and contributes not only to the rate of heart disease but also to the risk of vascular conditions (e.g., stroke, mesenteric ischemia, peripheral vascular disease, aortic dissection, and abdominal aortic aneurysm).

Table 182-1

Physiologic Changes of Aging and Potential Effects

PHYSIOLOGIC CHANGE POTENTIAL EFFECT
Nervous System  
Decreased efficiency of blood-brain barrier Increased risk of meningitis
  Potential for exaggerated medication responses
Decreased response to changes in temperature Impaired thermoregulation
Alteration of autonomic system function Variations in blood pressure; risk of orthostatic hypotension
  Reduced erectile function
  Urinary incontinence
Alterations in neurotransmitters Slowing of complex mental functioning
Skin and Mucosa  
Atrophy of all skin layers Decreased insulation
  Increased risk of skin injury
  Increased risk of infection
Sweat glands decreased in number or activity Potential for hyperthermia
Musculoskeletal System  
Progressive bone loss Increased risk of fractures
Atrophy of fibrocartilaginous and synovial tissues Joint instability and pain
  Impaired balance and mobility
Decrease in lean body mass Alteration in pharmacokinetics
Increase in proportion of adipose tissue Alteration in pharmacokinetics
Immune System  
Decrease in cell-mediated immunity Increased susceptibility to neoplasms
  Tendency to reactivate latent diseases
Decreased antibody titers Increased risk of infection
Cardiovascular System  
Decreased inotropic response Less efficient response to myocardial wall stress
Decreased chronotropic response Decreased maximal heart rate
Increased peripheral vascular resistance Increased blood pressure
Decreased ventricular filling Changes in organ perfusion
Pulmonary System  
Decreased vital capacity  
Decreased lung and airway compliance Increased airway resistance
Decreased chemoreceptor response to hypercapnia or hypoxemia Potential for rapid decompensation
Decreased ventilatory drive Decreased PaO2 and increased PaCO2
Decreased diffusion capacity Decreased PaO2
Hepatic Function  
Decrease in hepatic cell mass Reduced ability to regenerate
Decrease in hepatic blood flow Alteration in pharmacokinetics
Alterations in microsomal enzyme activity Alteration in pharmacokinetics
Renal System  
Decrease in renal cell mass Decreased drug elimination
Thickening of basement membrane Decreased drug elimination
Reduced hydroxylation of vitamin D Risk of hypocalcemia, osteoporosis
Decrease in total body water Alteration in pharmacokinetics
Decreased thirst response Risk of dehydration and electrolyte abnormalities
Decreased renal vasopressin response Risk of dehydration and electrolyte abnormalities
Gastrointestinal System  
Decrease in gastric mucosa Increased risk of gastric ulcer
Decrease in bicarbonate secretion Increased risk of gastric ulcer
Decrease in blood flow to gastrointestinal system Increased risk of perforation
Decreased epithelial cell regeneration Longer healing times

Because of several changes that occur with aging, elders are at higher risk for infections. Prostate disease in men and incomplete bladder emptying in women with pelvic floor abnormalities predispose to urinary tract infections. Microaspiration increases the risk of pneumonia, and fragile, aging skin prone to injury and breakdown increases the risk of infections of the skin and soft tissues. Immunosenescence of cell-mediated immunity predisposes patients to reactivation of latent diseases (e.g., tuberculosis) and may be associated with increased susceptibility to neoplasms. Cancer is the second most common cause of hospitalization and death in older patients.5

Fractures are the fifth leading cause of hospitalization, reflecting the high rate of osteoporosis, particularly in women.4 Arthritis is the most prevalent outpatient disease in elders because of the wear on cartilaginous joints, particularly of the knees, hips, and hands.4 Arthritis greatly affects quality of life, and these patients report fair or poor health approximately three times more often than patients without arthritis do.

Although the physiology of aging often affects a patient’s functional status, laboratory values are usually within the normal range. Abnormal laboratory values in elders should be evaluated as abnormal findings and should not be attributed to “normal effects of aging.”

Pharmacologic Considerations

Polypharmacy, drug interactions, and misuse and abuse of medications in elders are crucial health care issues. Elders currently consume more than 30% of the prescription drugs in the United States, and this figure is projected to increase to 50% by 2020. More than 40% of elders use five or more drugs weekly, and more than 10% use ten or more.6,7

Although multiple medications may be necessary to treat the medical problems that occur with aging, significant adverse health effects may result. Underlying medical problems, multiple physicians, changing pharmacokinetics of aging, and treatment of side effects of one medication with another drug are all contributory. Twelve percent to 30% of admitted elders have adverse drug reactions or interactions as a primary or major contributing factor to their admission, and 25% of these drug reactions or interactions are serious or life-threatening.6,7

Pharmacokinetics may change with age. Altered gastrointestinal motility and blood flow, decreased lean body mass, increased proportion of adipose tissue, decreased creatinine clearance, and decreased hepatic blood flow may alter the absorption, distribution, and clearance of medications. Despite these changes, the bioavailability of most medications is not significantly altered in elders. Medication interactions and side effects pose significant problems, however, particularly because many elders take multiple medications. Emergency physicians may unwittingly contribute to this problem by adding a new medication at discharge that may have an adverse drug interaction with a patient’s preexisting medications. In addition, the altered pharmacokinetics in elders necessitates caution when medications are administered in the ED, particularly sedative-hypnotics and narcotics. For these agents, a good rule of thumb is “start low and go slow.”

Several medications frequently used in the outpatient elder population are considered to be “potentially inappropriate medications.” This list includes but is not limited to narcotic analgesics, nonsteroidal anti-inflammatory agents, sedative-hypnotics, muscle relaxants, and antihistamines.8–10 These agents are generally not recommended for use in this population of patients and should be used sparingly.

The medications most often implicated in adverse reactions in elders in the ambulatory setting are cardiovascular medications, followed by diuretics, nonopioid analgesics, hypoglycemics, and anticoagulants.11,12 Caution should be used in prescribing any of these classes as they can contribute to morbidity and mortality in this age group.

The various analgesic medications used in the elderly can cause a wide range of adverse reactions and interactions. Narcotics and sedative-hypnotic agents can decrease cognition and increase the risk of falls and accidents. Nonsteroidal anti-inflammatory drugs (NSAIDs) may have serious and potentially lethal side effects. The toxicity of NSAIDs includes azotemia, worsened hypertension, and congestive heart failure as a result of sodium retention. Gastrointestinal toxicity ranges from bleeding to perforation.13 The data support use of extreme caution in prescribing NSAIDs. These complications can be seen in patients taking widely available over-the-counter formulations of these drugs. The significant increase in cardiovascular risk with the use of cyclooxygenase 2 inhibitors has led to a dramatic decrease in the use of these agents.

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