It is well known that we are an aging society with 20% of the population reaching 65 years or older by the year 2030.¹ Older Americans have more chronic conditions such as osteoarthritis, atherosclerosis, cancer, and diabetes, contributing to increased health care costs, one-third of the total annual health budget today. In the older patient population, pain is the most common symptom noted when consulting a physician.² There are multiple sites and causes of these painful conditions, including lower back (40%), arthritis (24%), previous fractures (14%), and neuropathies (11%).³

Despite the well known association of aging and chronic painful conditions, pain remains underreported and undertreated. Reasons for undertreatment are related to fear, bias, and education from health care providers (HCPs) and from patients themselves. Patients often believe that pain is inevitable, a normal part of aging, and they fear adverse effects from treatment. They are apprehensive about underlying cancer and addiction to analgesics. Health professionals may mistakenly believe that older patients have a higher pain tolerance and fail to inquire about pain. Many of the chronic conditions manifesting pain in older patients are not curable; however, there must be a focus on the management of the pain associated with these chronic conditions.

The American Geriatrics Society and American Medical Directors Association have published guidelines for the assessment, treatment, and monitoring of chronic pain in older patients, advocating individualized pain management, which is vital to patients with multiple underlying chronic diseases.^4,5 A number of treatment modalities have been demonstrated to be effective for older persons. Pharmacologic and nonpharmacologic options should be considered in the context of the patient’s beliefs, goals, and desires. Combining these options helps keep drug effects lower.⁶ With advancement in research and newer treatment options, regimens can target chronic pain while addressing comorbid conditions specific to the older patient.

This chapter will explore pain in the older patient. We address the neurophysiology, assessment of pain in cognitively intact and non-intact patients, and psychosocial issues associated with pain in this clinical population. Traditional treatments including pharmacologic and nonpharmacologic treatments are discussed; complementary and alternative methods for pain treatment, as well as extended care facilities and pain at the end of life, are also reviewed.

Age-related functional, structural, and biochemical changes of the pain pathways have been reported.⁷ The effects of age on the human brain are extensive, involving changes in structure, neurochemistry, and function.⁸ Excitatory and inhibitory mechanisms in the nervous system exert differential effects that contribute to the experience of pain and depend on complex communications among neural systems. There is strong evidence of progressive, age-related loss of serotonergic and noradrenergic neurons in the dorsal horn, suggesting impairment of the pain inhibitory system.^9,10 Functional consequences of structural age-related changes are difficult to extrapolate because of the highly integrated nature of pain processing; however, several patterns have emerged from the literature. Unmyelinated and myelinated peripheral nerves decrease with age, and increasing age shows signs of related damage or degeneration of sensory fibers.^11,12 Neurotransmitters of primary sensory nerves, substance P, and calcitonin gene-related protein are found at lower levels with increasing age, reflecting a reduction in the density or functional integrity of nociceptive nerves.¹³

Decreased acuity for pain may place older people at greater risk of tissue damage.¹⁴ Despite these changes, age does not produce a change in the pain stimulus-response curve.¹⁵ Reports of increasing pain with age occur when stimuli are intense or persist for longer periods. The widely held belief that older persons do not experience pain with the same intensity as younger persons is not supported by the literature. Increased pain threshold to noxious thermal, mechanical, and electrical stimuli with age has been shown in more than 40 studies, yet there was no agreement among studies. An increased pain threshold could result in less time between the alerting pain and the onset of tissue injury, which puts the older patient at greater risk.

Nerves that have been injured by trauma or disease can become more sensitive. Older persons are more likely to have slow resolution of peripheral sensitization despite tissue healing that leads to prolonged pain states not seen in younger persons. In addition to their prolonged time to heal, older persons are more likely to demonstrate slower resolution of hyperalgesia.¹⁶ Under circumstances where pain is likely to persist, older persons are especially vulnerable to the negative impacts of pain.

Assessment of pain in the older patient is difficult because patients commonly have physical limitations with loss of vision and hearing, and some patients present with cognitive impairments or dementia. Nevertheless, these patients have need of adequate pain assessment as they have many sources and reasons for pain related to aging. Taking the time to teach the older patient how to use the assessment scale and use of a pain assessment scale that meets the patient’s needs can provide a fairly accurate rating for pain intensity.

Older patients who have pain may fear the pain they are experiencing because it means a disease is progressing or is a new disease. Many older patients want to be seen as good patients and feel that the pain they are having is just a part of the aging process and do not report pain concerns. Pain can also be a threat to independent living, leisure activities, and self-esteem, leaving patients feeling less worthwhile if they admit to having pain every day.¹⁷

Creation of a sense of trust is important to obtain the salient information needed for a good pain assessment. Reassuring the patient that he or she needs to report pain and that the reports of pain will be respected can go a long way in determining the best way to treat the patient’s pain.

The basic elements of pain assessment can be used effectively with the older person. Asking the patient about the location and duration of the pain, intensity, description, aggravating or alleviating factors, functional impairment, and cognitive impairment can provide the base for the assessment.^17,18 In the older patient cognitive impairment and functional impairment may be key indicators for pain. Pain may be interfering with sleep, which may make it much more difficult for patients to concentrate and may cause the patient to appear disheveled in appearance or seem confused.¹⁷

Most cognitively intact older persons can use the numeric rating scale (NRS) based on ratings of 0-no pain to 10-worst pain possible. A systematic review found that single item pain ratings were a reliable and valid measure of pain intensity.¹⁹ The NRS is best used to determine if pain interventions have been successful in reducing pain levels. If the patient reports a decreased pain rating of 2 points on the NRS or 30%, the decrease is considered to be clinically significant.²⁰ If using a written pain assessment scale, using off-white paper with larger, bolder print will make it easier for the older patient to see what is written.

When the older patient has chronic pain, a comprehensive pain assessment tool such as the brief pain inventory (BPI) or the McGill Pain Questionnaire (MPQ) not only can help determine the intensity of the pain but also provide information on activity and pain medications as well as determine descriptions. One helpful element of these tools is the use of a pain diagram where the patient can mark the location of the pain on a body diagram.¹⁷

There are pain assessment scales using pain behaviors that have been developed to assess pain in patients who cannot self-report pain. Before using a behavioral scale recommendations include asking the patient to self-report the pain intensity, attempting to identify any potential causes of pain, taking time to observe the patient especially with movement, asking the family or caregivers about behaviors that would indicate pain, and attempting an analgesic trial to see if the behaviors resolve.^18,21

Behaviors identified as indicating pain include vocalizations, facial grimacing, bracing, rubbing, restlessness, vocal complaints such as moaning, changes in interpersonal behaviors such as resisting care and being disruptive, and changes in mental status such as confusion, irritability, and distress.^22,23,24

Although the behavioral tools we are currently using to assess pain in the older patient are not as good as they will be with more research, they provide a method for assessment of pain in the nonverbal older patient. A behavioral tool currently used is the Modified FLACC scale, which uses facial expression, restlessness, and body tension that are rated using a 0 to 10 pain intensity composite rating. The Pain Assessment in Advanced Dementia Scale (PAINAD) is a behavioral tool designed for use with Alzheimer patients. The tool uses breathing, negative vocalizations, facial expression, body language, and consolability that is rated to derive a 0 to 10 pain intensity rating.²⁵ Additional pain assessment tools for older persons include Pain Assessment Checklist for Seniors with Limited Ability to Communicate (PACSLAC), Functional Pain Scale (FPS), and Dolophus-2.¹⁸

Older patients with pain can feel depressed, isolated, and at risk for loss of independence. If pain is not adequately treated, older patients may find that they cannot function as well as they did prior to the onset of pain. Overall functionality can be impaired, resulting in deconditioning. Some older patients feel that pain is just a part of normal aging. Although patients may have a higher number of comorbidities that can produce painful conditions such as diabetic neuropathy, they should be afforded the opportunity for pain management to reduce pain and the unwanted effects of unrelieved pain.

Financial concerns also impact the way older patients report and treat pain. Patients who cannot afford clinic visits and medications will have untreated pain that can heavily impact functionality. This can lead to undertreated or untreated pain that results in depression, anxiety, decreased socialization, disturbed sleep, impaired ambulation, increased health care utilization and subsequent costs, impaired cognition, and altered nutrition.^24,26 Assessment of older patients for depression and other psychosocial effects at clinic visits can help pinpoint the effects of untreated pain and identify patients’ needs.