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11 Articles in Volume 14, Issue #10
Combating Opioid-Induced Constipation: New and Emerging Therapies
Updates on Smoking and Low Back Pain
Unraveling the Psychological Mechanisms Behind Smoking in Chronic Pain
Addressing Psychosocial Factors in Pain Management in the Emergency Department
Long-Term Outcomes and New Developments in Juvenile Fibromyalgia
Pain Management in the Elderly: Etiology and Special Considerations
Using Pharmacogenetic Testing in a Pain Practice
Editor's Memo: Care With Caution
Ask the Expert: HIPAA Rules
Ask the Expert: DMARDs and Opioids
Letters to the Editor: November/December 2014

Pain Management in the Elderly: Etiology and Special Considerations

There are many physical changes that take place during the aging process that can influence pain processing. This does not mean that acute or chronic pain is a natural part of aging. Understanding the special needs of an aging population is an important aspect of pain management in this patient group.

The United States is on the verge of what is referred to as a “longevity revolution”—a phenomenon that is occurring as the population of elderly individuals (aged 65 years and older) increases. Currently, 12% of the population, or 38 million Americans, fall into this category. By 2030, it is projected that the number of elderly individuals will reach 72 million, approximately 20% of the US population. In addition, individuals over 80 years of age are the fastest growing age group worldwide.1

The growing elderly community is at high risk for chronic pain conditions. The Institute of Medicine report, Relieving Pain in America, has highlighted the fact that the prevalence of pain has been increasing among all age groups but is consistently greatest among elderly Americans.2 It is estimated that approximately 30% of the elderly population suffers from chronic pain.1 Typically, elderly patients are more likely to report pain in multiple locations, and elderly women are more likely to report pain than elderly men.3 Moreover, these older Americans have the highest long-term rate of consumption of medications for pain.2

The good news is that many elderly individuals are very productive and remain active.4 The Centers for Disease Control and Prevention has reported that the majority of adults aged over 65 years continue to work, volunteer for humanitarian causes, travel, and remain relatively active. Individuals who have aged successfully have the following traits5:

  • Avoidance of debilitating diseases and disability
  • High physical functioning, which enables them to live independently and engage in normal daily life activities
  • Maintenance of cognitive function by actively engaging in mentally-stimulating and challenging activities, and pursuit of social and productive activities
  • Resilience to cope with physical, social, and emotional changes
  • Perception of control over life circumstances

In Part 1 of this two-part series we will discuss the etiology of pain conditions. Part 2 will review treatment considerations.

Special Concerns in Elderly Populations

Assessment of pain in the elderly population raises special considerations. It is widely believed that the elderly are less sensitive to pain and that pain is a normal part of the aging process, leading to possible under-treatment of pain.6 In addition, many elderly patients may downplay their pain in the face of other significant events, such as loss of independence or death of a spouse, or comorbidities, such as diabetes and heart disease.7 Studies have shown, however, that loss of a spouse (mourning, depression) has been associated with increases in the likelihood of pain.8

It appears that certain pain conditions increase with age (ie, degenerative joint disease), whereas others decline with age (those that have a work-related mechanical component). An increase in the prevalence of persistent pain,9 joint pain,10 and central sensitization syndromes such as fibromyalgia11 have been reported in the elderly.6 It appears that chest, upper back, stomach, and headache pain do not change in prevalence throughout a person’s lifespan, whereas abdominal and orofacial pain that is unrelated to mechanical use tend to decrease in prevalence as one ages.3 In addition, older adults generally have a higher number of painful comorbidities, such as diabetic neuropathies, osteoarthritis, fractures and injuries from falls, compression fractures from osteoporosis, and impaired circulation, that are directly related to painful symptoms.12

Many physiological changes through the aging process can increase pain and affect quality of life. These physiological changes affect the skin, bones, joints, and the urinary, muscular, hormonal, sensory, vestibular and cardio-respiratory systems. In addition, elderly patients have age-related issues, including memory problems, dementias, increased use of multiple medications, and different nutritional needs than younger patients.4,13,14 A review of physiological changes related to aging and pain are highlighted here.

Body Composition

Alterations of body composition are a common part of the aging process. In particular, the elderly usually have an increase in fat mass and a decrease in lean body mass (ie, any body mass that is not fat, such as bones, muscle, organs, water weight, etc.), which results in thinner skin and loss of skin elasticity due to the skin fat deposits being redistributed into the trunk.4,15 This loss of elasticity will cause the skin to sag and lose color by the fifth decade.4 The loss of some of the protective fatty layer in the skin that helps cushion one’s blood vessels leads to easier bruising from burns and injuries.16 This redistribution of fat from the skin to the organs, as well as increased water retention and decreased blood flow, affects how medications are metabolized in the body: drugs may remain longer and break down slower. This means that pain medications may take longer to be effective, but does not necessarily mean that their effects will last longer; it depends on what the medication is used for.12 However, because the medication may take longer to be effective, it can create a tendency for patients to consume higher doses than required or advised.

Sensory System

The sensory systems also start to become compromised through the aging process. Vision becomes less sharp as the lens of the eye begin to harden and lose transparency, and the pupil gradually shrinks to allow less light to penetrate.4 Cataracts and glaucoma are more likely to occur.4 In addition, hearing ability decreases, particularly the ability to hear high-frequency consonants (eg, s, t, and z).4 Loss of sight and hearing also raises the risk for falls and accidents that can be painful.

Tactile sensation, such as changes in pain perception, vibrations, cold, heat, pressure, and general touch sensations decrease due to decreased blood flow and increased nerve damage due to higher blood sugar levels.12,17 Decreased temperature sensitivity increases the risk for conditions such as hypothermia or frostbite,4 which means that special care must be taken for the elderly living in cold-weather climates to prevent these painful conditions and that cold/heat therapy for pain management must be carefully monitored to prevent damage.

Neuropathies and other conditions also can compromise an elderly individual’s sensory systems, with common symptoms of struggling to maintain a steady gait and balance increasing the incidence of fractures due to falls.12

Urinary System

The urinary system also becomes less efficient through the aging process, in part because of increased prescription medication usage. At the age of 70, kidneys are 50% less efficient at waste filtration than at age 30.4 Patients also may need to urinate more frequently. This occurs because the bladder’s capacity reduces by half from age 30 to 70.4

Urinary incontinence affects 15% to 30% of the general geriatric population, and can pose emotional issues of fear and embarrassment, which may lead to social isolation and avoidance.4 Usually urinary incontinence is caused by medications or treatable neurological issues and can normally be resolved once treated.4 When prescribing medication for pain management, side effects such as urinary incontinence need to be considered. Limited kidney and liver function increase the half-life and alter the excretion process of medications,12 increasing the risk for possible drug overdose.

Bone Composition

By the fourth decade, bone mineral (eg, calcium) loss exceeds mineral accumulation, resulting in weaker, more porous bone tissue.4 Although the process occurs in both men and women, it is more common and begins earlier in women.4,14 Bone density loss can be accelerated by reduction in physical activity and decrease in appetite, which may cause nutritional deficiencies in elderly adults.14 Mineral loss can lead to the progressive breakdown of joint cartilage (osteopenia/osteoporosis), and, if it is severe enough,13 it can increase the risk for bone fractures and spinal stenosis.4,14

Osteoarthritis is the leading cause of disability affecting the quality of life of almost 21 million Americans. Bones and joints, particularly the hip, wrist, and spine, may become so fragile that they are easily susceptible to fractures during typical daily activities. Progressive deterioration of bone density that occurs with age is linked to physical inactivity, lack of proper nutrition, and hormonal and genetic factors.

With aging, muscle mass progressively decreases. Muscle fiber size and number decrease, with a loss of 10% of muscle fibers after age 50.18 This decrease in muscle mass is called sacropenia, and it can diminish quality of life by making simple daily activities more difficult and painful, and by increasing the risk for falls.4,13,14 As with osteoporosis, sacropenia results from physical inactivity—motor neurons become less coordinated or are lost with less innervation of muscle fibers, particularly fast twitch fibers (type 2). This results in loss of strength, coordination, and power.13,14

The good news, however, is that aging does not reduce the ability of the musculoskeletal system to adapt to resistance exercise, allowing individuals to counter the aging process by increasing muscular strength, power, and endurance, resting metabolic rate, bone mineral density, and physical function, and by decreasing body fat.13

Cardiovascular Function

Cardiovascular function declines through the aging process because of a decrease in maximal heart rate, in part because patients may no longer be partaking in physical activity. Cardiovascular inefficiencies cause decreases in peripheral blood flow, which magnifies the importance of warm-ups and cool-downs before and after physical activity to prevent blood pooling and aid in reducing the heart rate.14

As noted, with decreased peripheral blood flow also come a decrease in pain sensitivity in the periphery, which may mean that the elderly may accidentally damage themselves without being fully aware. Ensuring a well-maintained cardiovascular system will help in recovery and healing processes as well, because increased blood flow will pump blood more efficiently to the damaged areas, aiding and accelerating the healing process.

Comorbidities

In addition to the physical aging process discussed above, old age is marked by an array of psychosocial conditions that can influence the pain experience of the elderly. Comorbidities such as depression, anxiety, insomnia, and dementia can modulate perceived pain intensity, increase the probability of pain interfering with daily life, complicate treatment, and lower quality of life.

Depression

Depression is characterized by low mood, sadness, and hopelessness. It is understandable that depression and chronic pain frequently occur together. For people who live with chronic pain, daily life is a struggle. It is difficult for them to work, complete household chores, sleep, or even have fun. This can negatively affect mood and lead to depression in many cases. In a sample of pain clinics and inpatient pain programs the prevalence of depression in chronic pain populations ranged from 25% to 87% and the prevalence of pain in patients with depression ranged from 15% to 85%, suggesting high comorbidity between chronic pain and depression.19 Bodily pain is listed as a symptom of depression, and it has been found that people with more severe depression feel more intense pain.20-23They also may feel more dependent and perceive themselves to have decreased control over their lives, which can make pain management more difficult.

In elderly populations, the dynamic between chronic pain and depression often can go unnoticed. This is because the symptoms associated with chronic pain and depression can be mistakenly attributed to the aging process. For instance, aging is associated with decreased frequency and intensity of activities of daily living (ADLs). Although ADLs decrease as one ages, chronic pain can severely limit the ADL24 and increase fear of movement, which further decreases ADLs, inadvertently increasing pain. It is possible that limited ADL leads to feeling low, helpless, hopeless, and irritable (all symptoms of depression). Studies found that depression mediates the relationship between chronic pain and physical functioning in the elderly.25-27

Chronic pain also has a strong affective component that can influence mood and emotions, which then negatively influence ADLs.25,27 The comorbidity of chronic pain and depression is a potential complication for treatment because they feed on each other. Pain interferes with recovery from depression, while depression makes it more difficult for pain to be treated and can increase the chance the patient will not complete rehabilitation.

Anxiety

Anxiety is referred to as feelings of worry, fear, and unease about the future. Anxious people tend to have heightened physical sensations and, in the context of chronic pain, anxious arousal can lower pain tolerance.28 Lowered pain tolerance increases the chance that pain will interfere with ADLs and increase depression. Pain in the elderly may be exacerbated by their worry that the pain impairment will be so great they cannot complete their daily activities, and beliefs about their condition, such as what their chronic pain condition may mean to them, increase their anxiety.

As the elderly age, their network of family, friends, and acquaintances shrinks. They may have fears about their family members dying, or they may even worry about their own death. In addition, they may worry about what the future holds in store for them: will they be unable to function and take care of themselves? Will they need to move to an assisted living facility? They may even worry about how much they are worrying! This creates a vicious cycle between chronic pain and anxiety, with anxiety increasing muscle tension and becoming a potential pain source.29

Although research has been done on the relationship between chronic pain and anxiety, few studies have been completed in an elderly population. In one such study, it was found that patient-report clinical anxiety was related to chronic pain.30 Elderly subjects who were anxious expressed more localized pain complaints and reported more intense pain than their non-anxious counterparts. Although the elderly report anxiety, this state can go unnoticed; the elderly often do not report emotional responses to pain, especially when their anxiety is not accompanied by depression.31

Insomnia

Unfortunately, changes in sleep patterns are part of the normal aging process. As people get older, they tend to have more difficulty falling and staying asleep. These changes are influenced by several factors. The first is sleep architecture, or the depth of the sleep stages. Although the amount of total sleep time remains relatively constant, older people spend more time in light stages of sleep compared to younger people. Therefore, it is easier for them to wake up in the middle of the night. In addition, continence problems in women and prostate enlargement in men can increase the likelihood that the elderly wake in the middle of the night.

Despite these changes, as long as older adults wake up feeling restful and refreshed, are not sleepy during the day, and do not need to nap, they are probably getting adequate sleep. Problems arise if the elderly feel tired and fatigued upon waking up, and have difficulty falling or staying asleep at night. These problems could be indicative of insomnia. Insomnia refers to difficulty initiating sleep, difficulty staying asleep, waking early in the morning, or any the combination of the three. Insomnia is accompanied by daytime consequences, including daytime sleepiness, fatigue, impaired cognition, memory problems, irritability, psychomotor dysfunction, and decreased alertness and concentration.32

The National Science Foundation’s Sleep in America poll reported that 44% of older persons experience at least one nighttime insomnia symptom several nights per week.33 These insomnia symptoms often are exaggerated in patients with chronic pain.34,35 Acute pain leads to short-term poor sleep that can be modified with pain/sleep management. However, when pain becomes chronic, it leads to long-term poor sleep. Inadequate sleep can heighten pain sensations the next morning. Heightened pain, in turn, will make it difficult for people to fall asleep. Pain also makes it more difficult for people to stay asleep because movement will intensify pain sensation. This relationship is likely to evolve into a vicious cycle, disrupting daily activities, creating stress, causing worry, and lowering mood, leading to a decreased quality of life. This cycle is illustrated in Figure 1.

The ability to fall asleep and maintain sleep also is influenced by the environment, such as room temperature. Because of changes in fat deposition and the thinning of their skin, many elderly adults set the thermostat of their house higher. Lowering the temperature slightly at night may be beneficial because a cooler temperature increases the likelihood of falling asleep. Familiarity with the bedroom also is another contributing factor. If the patient spends nights in a hospital or nursing home, staying in an unfamiliar room and/or having roommates may make it more difficult for them to fall asleep. Those environments also may be associated with more nighttime activity, perhaps with noise and bright lights in emergency situations. In addition, bedtime routine may be disrupted by loss of a spouse or loss of independence.

A tendency to ruminate (associated with high anxiety) also contributes to difficulty falling asleep. Common rumination topics include loss of loved ones, fear of dying, and frustration at loss of independence and dignity. In the elderly, sleep disturbance also can be attributed to medications, such as long-term use of pain medications, because they can lessen sleep quality by disrupting REM cycles and decreasing the length of sleep.

Insomnia not only increases the chance of experiencing pain, it also increases risk for accidents, since lack of sleep makes people less alert and more likely to make mistakes. Therefore, older people are encouraged to talk to their doctors if they have sleep problems. Several tips for having a restful sleep can be found in Table 1.

Dementia/Confusion

Memory lapses also occur more frequently as people get older, and these lapses may be due to many things, including drug interactions, vascular deficiencies, and hormonal or biochemical imbalances. Generally, memory lapses occur less frequently in populations that have maintained good cardiovascular health and have kept their mind active.4 As with physical characteristics of the body, the “use it or lose it” principle applies to brain acuity.4 Although some memory difficulty is expected with aging, the memory issues associated with dementia are more severe.

Dementia is derived from the Latin word, meaning “out of one’s mind.” Dementia actually refers to a group of diseases that share a global decline in intellectual capacity and performance that is gradual in onset and associated with progressive social incapacitation.36 Elderly patients with dementia are likely to be confused. There is a quick test to assess the confused state; ask the patient if they know:

  • Their name
  • Their current location
  • The time (day or date or month or year).

As dementia gets more severe, it becomes more difficult to give correct answers.

Dementia is not a normal consequence of aging, and it often occurs with chronic pain. A review on pain in people with dementia found that pain is not less frequent or less intense in people with dementia.37 On the contrary, it is likely that any sign of pain made in the presence of marked cognitive impairment requires even greater attention. Due to the difficulty in verbal communication, the pain in older people with dementia can be undertreated or untreated. In this situation, the assessment of pain will be done through observation. Consequently, this can add another task for the caregivers: they need to be alert and observant for non-verbal signs of pain, which are listed in Table 2.38,39

In addition, memory capabilities need to be considered when prescribing medication, to ensure the patient does not accidentally overdose or forget to take a necessary medication. Many prescription drugs are associated with dangerous interactions, and adverse side effects are even greater in much of the older population due to reduced cardiovascular, kidney, and liver function.4 In addition, many pain medications can cause complications, including constipation and urinary retention.

Summary

There are many natural physical changes that take place during the aging process that can influence pain processing. These include the body’s changing composition of fat deposits, muscle mass, and bone density, as well as decreases in sensory systems, kidney, and cardiovascular functioning. These processes do not mean that acute or chronic pain is a natural part of aging or that they should be written off as “acceptable losses.” Understanding the special needs of an aging population, including comorbid factors such as anxiety, depression, insomnia, and dementia that can increase pain, is an important aspect of pain management for the elderly.

 

Last updated on: February 19, 2015

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