The prevalence of generalized fatigue in older adults varies from 5% to almost 70% depending on the assessment used, the characteristics of the older adult population, the time of day fatigue is assessed, and the cut-points used to indicate fatigue. Regardless of the assessment tool, fatigue is associated with decreased function and increased mortality. In a study of 492 older primary care patients, the question “Do you feel tired most of the time?” identified older adults with a one and a half to almost twofold increased risk of mortality over 10 years. Other assessments for fatigue tend to be more involved and many tools exist, again, predominantly derived from oncology. The Brief Fatigue Inventory, a nine-item instrument that assesses severity of fatigue and the impact of fatigue on daily functioning in the past 24 hours, has good psychometric properties but has been predominantly used in cancer populations. More recently, the concept of fatigability developed as a complement to the symptom of fatigue. Fatigability measures how fatigued an individual feels in relation to defined activities (eg, how fatigued a person feels after a 5-minute treadmill test. It offers a more standardized way to measure fatigue but is more difficult to integrate into standard practice.
Questions in the assessment of fatigue should address (1) when the fatigue began, whether the onset was sudden or more gradual; (2) the pattern of fatigue over the course of a day; (3) what exacerbates or improves the fatigue; and (4) the impact that fatigue has on daily function and relationships. Sleep characteristics and medications should be reviewed. Because psychological factors are often associated with fatigue, systematic assessment for depression is warranted.
The biopsychosocial model, commonly used to characterize pain, applies well to other symptoms, including fatigue. The biopsychosocial model posits that psychological, social, spiritual, and physical factors influence an individual’s symptoms (Figure 57-2). In the case of fatigue, other factors such as depression, social isolation or complexity, and spiritual distress may influence the experience of fatigue. A number of physical conditions are characterized by fatigue including electrolyte disturbances, occult malignancy, polymyalgia rheumatica, occult hepatitis, or HIV. Fatigue may be a silent harbinger of anemia or infection. In older adults, where atypical presentations of acute conditions are common, new-onset fatigue may indicate a recent myocardial infarction (MI) or heart failure. Hypogonadism is a less common cause of fatigue. Findings from the history and physical examination should dictate further diagnostic evaluation.
Very few studies have addressed the management of fatigue in older adults. Nonpharmacologic approaches that have promise include increased graded exercise therapy and cognitive behavioral therapy (CBT). However to date, the authors know of no clinical trials that evaluated the use of CBT for fatigue in older adults. Improvement of older adults’ sleep hygiene through both nonpharmacalogic and pharmacologic strategies (see Chapter 49) may reduce fatigue. While antidepressants may be beneficial, antidepressants with strong anticholinergic effects should be avoided (see Chapter 73). In the palliative care setting for older adults with advanced or life-limiting illnesses, psychostimulants such as methylphenidate or modafenil may be considered. In a study of predominantly older prostate cancer patients (ages 52–94), methylphenidate reduced fatigue severity compared to control. However a number of patients had to discontinue treatment due to increased blood pressure and tachycardia. A recent within-person crossover trial cast doubt on methylphenidate treatment of fatigue in advanced cancer. Among 43 participants who alternated between methylphenidate and placebo three times over a 9-day period, no improvement in fatigue during days with methylphenidate was observed. In older adults with known cardiovascular disease or arrhythmias, psychostimulants should not be used. While anecdotal reports touted the benefit of donepezil in treatment of opioid-induced fatigue in cancer patients, a subsequent clinical trial did not support these claims. In summary, fatigue is a common condition in older adults with likely multiple factors contributing to its prevalence.
Evaluation of Dyspnea (Breathlessness)
Due to the high rates of COPD and heart failure in older adults, along with an array of other comorbid conditions, shortness of breath (dyspnea) is very common in older adults. In an Australian primary care practice, over half of those who presented with shortness of breath were over the age of 65. The prevalence of dyspnea in community-dwelling older adults ranges between 17% and 62%, depending on the population studied and cut-point used to define “dyspnea.” Dyspnea will likely occur at some point during a number of serious illnesses experienced by older adults (eg, cancer, heart failure, advanced lung disease), and at the end of life. The biopsychosocial model applies to dyspnea as well as it does to fatigue. Anxiety, disappointment, financial stressors, and questions about meaning often contribute significantly to the experience of dyspnea. Dyspnea, in turn, serves as a source of patient and caregiver distress and is associated with decreased quality of life, decreased function, and increased health care utilization.
Physiologic mechanisms of dyspnea often fall under three categories: increased respiratory effort due to obstruction (eg, COPD, asthma, masses) or restriction (eg, obesity, pleural effusion); weakness (eg, multiple sclerosis, amyotrophic lateral sclerosis); or ventilation/perfusion mismatch (eg, anemia, pulmonary embolism, heart failure). More subtle systemic changes can contribute to the occurrence of dyspnea, especially at the end of life. For example, in the National Hospice Survey, 24% of patients with no known cardiopulmonary disease experienced dyspnea. The most appropriate measure of shortness of breath is the older adult’s self-report. Dyspnea does not always correlate with hypoxia, hypercarbia, or the presence of tachypnea. Most self-report tools to assess dyspnea come from the obstructive lung disease literature. One of the most common assessment tools is the Medical Research Council (MRC) breathlessness scale. First published in the 1950s, the MRC scale characterizes, through five statements, a range of disability caused by level of breathlessness (Table 57-1). It correlates well with other dyspnea scales and with other direct measures of function, such as walking speed.
TABLE 57-1MEDICAL RESEARCH COUNCIL BREATHLESSNESS SCALE |Favorite Table|Download (.pdf) TABLE 57-1 MEDICAL RESEARCH COUNCIL BREATHLESSNESS SCALE
|GRADE ||DEGREE OF BREATHLESSNESS |
|1 ||Not troubled by breathlessness except on strenuous exercise |
|2 ||Short of breath when hurrying on level ground or walking up a slight hill |
|3 ||Walks slower than most people on level ground, stops after a mile or so, or stops after 15 min walking at own pace. |
|4 ||Stops for breath after walking about 100 yd or after a few minutes on level ground |
|5 ||Too breathless to leave the house, or breathless when undressing |
Management of Shortness of Breath
Nonpharmacologic approaches to breathlessness have few side effects, unlike morphine for example, and avoid polypharmacy, a major concern in the older adults. They should be considered alongside pharmacologic approaches as first-line therapy. Nonpharmacologic approaches that can be helpful in the treatment of dyspnea include the use of a fan, breathing techniques, mindfulness and relaxation, anxiety management, and energy conservation. Breathing techniques that can reduce the sensation of dyspnea include pursed lip breathing, prolonged exhalation, and posture modification. In addition to mindfulness and relaxation, guided imagery and distraction strategies (eg, music, TV, reading by self or caregiver) were shown to reduce the sensation of breathlessness.
In patients with COPD and hypoxia, long-term oxygen therapy increases quality of life and prolongs survival. Likewise, in a subset of patients with COPD, noninvasive ventilatory support such as with bilevel positive airway pressure (BiPAP), can improve quality of life and prolong survival. In patients with advanced cancer and other nonpulmonary causes of dyspnea, the value of oxygen in improving outcomes is less clear. These results may be in part due to the fact that less than half of advanced cancer patients with dyspnea are hypoxic. In a study of nasal cannula-delivered air versus nasal cannula-delivered oxygen (median age 65), no difference was found in dyspnea relief between the two modalities when patients were not hypoxic; in two studies of hypoxic cancer patients, more benefit from oxygen was noted. Recent studies of noninvasive ventilation in advanced cancer patients suggest that it may improve symptoms. In a multisite study of 200 predominantly older adults with advanced cancer (mean age 71), noninvasive ventilation was more effective than oxygen in reducing dyspnea and decreasing the amount of morphine needed to control symptoms. However, more patients in the noninvasive ventilation arm discontinued treatment primarily due to mask intolerance and anxiety.
Pharmacologic treatment for dyspnea should first and foremost be directed to the underlying cause of dyspnea, if known. Treatment may include a β-agonist for COPD or a diuretic in the case of heart failure. In a subset of patients, breathlessness persists at rest or on minimal exertion despite optimal treatment of the underlying chronic condition. These patients are described as having refractory dyspnea. In patients with refractory dyspnea, opioids may be beneficial. A number of studies of opioids for the treatment of refractory dyspnea in the setting of advanced illness demonstrate some benefit. However, the findings of reduced dyspnea (compared to control) are not consistent, and many studies remain underpowered to produce conclusive findings. Unfortunately, many of these studies use morphine, which has active metabolites (eg, morphine-6-glucornide, morphine-3-glucoronide). Morphine-3-glucoronide builds up in renal insufficiency, common in older adults, and is responsible for symptoms of neurotoxicity (eg, hyperalgesia, allodynia, myoclonus). In older adults, opioids are associated with decreased mental functioning. For some patients, decreased mental functioning will not be acceptable despite its potentially positive impact on breathing.