Pain in Older People Attending Emergency Departments

Patient

Underreporting, stoicism

Concerns about the meaning of pain, of the diagnostic tests and hospitalisation

Difficulties to use some assessment tools

Multiple problems making treatment more difficult

Polypharmacy—side effects of treatments

Health care providers

Failure to believe patient’s pain

Failure to use some validated pain assessment tools

Mistaking ageing for reversible and treatable disorders

Numerous myths, such as presbyalgesia, or that the prescription of analgesia leads to addiction and lack of long-term efficacy

The belief that failure to express pain complaints means they do not exist

Lack of education in the assessment and management of pain in older people in the curriculum of health professionals

The optimal management of acute pain in older adults requires an iterative process of detection, assessment, explanation, reassurance and treatment. This is true for all individuals with acute pain but particularly so for older adults because of the increased risk of adverse events. Thus, reassessment of pain is as important as providing initial treatment, and failure to reassess pain is a common cause of under-treatment of pain in older adults. Following the Assessing Care of Vulnerable Elders quality indicator approach, a task force convened by the Society for Academic Emergency Medicine and the American College of Emergency Physicians developed the following indicators to measure the quality of geriatric pain care received in the ED setting (Table 22.2) [28].

Table 22.2

Geriatric ED pain care quality indicators , adapted from [28]

1. Formal assessment for the presence of acute pain should be documented within 1 h of ED arrival

2. If a patient remains in the ED for longer than 6 h, a second pain assessment should be documented

3. If a patient receives pain treatment, a pain reassessment should be documented before discharge from the ED

4. If a patient has moderate to severe pain, pain treatment should be initiated (or a reason documented why it was not initiated)

5. Meperidine (Pethidine or Demerol) should not be used to treat pain in older adults

6. If a patient is prescribed opioid analgesics upon discharge from the ED, a bowel regimen should also be provided

22.2 Definition and Types of Pain

Pain is described as an unpleasant sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage [29]. Pain may be acute, lasting from seconds to weeks until complete healing, or it may be chronic, lasting for months or years, sometimes forever. Pain has a tremendous influence on peoples’ quality of life and functioning.

Acute pain plays an important role in drawing attention to injured tissues and preventing further tissue damage. Acute pain should trigger an urgent search for an underlying cause that might be immediately treated. Autonomic overactivity such as tachycardia and diaphoresis is often present.

Furthermore, older people often suffer from chronic or persistent pain for months to years, and as a result, they may be plagued by depression and anxiety, sleep disturbance, functional disability and compromised quality of life [24, 30–36]. The psychosocial impact of chronic pain is of greater importance in older people, not least because it can lead to emergency admissions in older people.

Most older patients will present nociceptive pain (stimulation of nociceptive receptors by a tissue injury process) secondary, for example, from osteoarthritis, soft tissue injuries and visceral pathology (Table 22.3). But some patients will suffer from neuropathic pain (pain initiated or caused by primary lesion or dysfunction in the nervous system) [29]. It is typically described as a sharp, tingling, burning or electric sensation that often radiates. Pain of neuropathic origin may be associated with dysesthesias (unpleasant abnormal sensations), hyperalgesia (mildly painful stimuli perceived as very painful) or allodynia (non-painful stimuli perceived as painful). This term encompasses a diverse range of conditions including painful peripheral neuropathies, post-herpetic neuralgia and central post-stroke pain. Neuropathic pain needs to be detected in the ED, because the management tends to be more difficult and requires a multimodal approach therapy.

Table 22.3

Pain classification

Nociceptive pain

Musculoskeletal conditions: osteoarthritis, degenerative disc disease, osteoporosis and fractures

Rheumatologic conditions: rheumatoid arthritis, temporal arteritis

Trauma

Cancer

Vascular disease

Central neuropathic pain

Ischemia, haemorrhages located in the thalamus, spinothalamic pathways or thalamocortical projections

Spinal cord injury

Inflammatory CNS disease (multiple sclerosis, myelitis, syringomyelia)

Peripheral neuropathic pain

Trigeminal neuralgia

Nerve compression

Neuroma

Plexus neuropathies

Metabolic, toxic, immune-mediated polyneuropathies

Infectious/parainfectious neuropathies: post-herpetic, syphilis

Finally, patients in the ED are at a high risk of procedural pain related to different investigations or interventions. This type of pain must be anticipated and adequately prevented.

22.3 Pain Assessment

Pain is a subjective, complex and multidimensional experience, for which there are no objective biological markers. Despite decades of effort, there is no neurophysiologic or chemical test that can measure pain in individual patients. Self-report is considered the most accurate and appropriate pain assessment method, as health care professionals often underestimate a patient’s pain [37–39]. Although sensory or cognitive impairment might affect patients’ ability to report pain, self-report should always be sought as first step in any assessment [40–43]. However, it should not be assumed that older patients will automatically report their pain. A careful patient history is also essential for discriminating neuropathic pain from nociceptive pain descriptors, to identify the underlying cause, to evaluate the impact of pain and the efficacy of our treatments. It is also crucial to acknowledge that the patient’s pain is real and that it will be addressed.

There are several self-report pain assessment scales, among which the visual analogue scale (VAS), the numeric rating scale (NRS), the verbal rating scale or verbal descriptor scale (VRS, VDS), the pain thermometer (PT) and the Faces Pain Scale (FPS) are the most frequently used [68]. Most of these scales have demonstrated an acceptable reliability and validity in older patients in different settings (acute care, pain clinic, nursing home, community dwelling) [29]. For example, in Herr study, intercorrelations between the scales (visual analogue scale, 21-point numeric rating scale, verbal descriptor scale, 11-point verbal numeric rating scale and Faces Pain Scale) were all statistically significant with correlations averaged between each scale pairing ranging from 0.78 to 0.94{Herr, 2004 #16}. It is important to choose the most adequate scale for each individual patient.

Patients need also to be asked when and how pain occurred, as well as the location and radiation. Duration and variation of pain should be assessed with questions such as ‘is your pain always there, or does it come and go?’ The presence of transitory exacerbations of pain (breakthrough pain) should be assessed. Asking the patient to describe the factors that aggravate or alleviate the pain helps to plan interventions. The impact of pain in daily life activities is very important in this population.

22.3.1 Dementia and Pain Assessment

The assessment of pain in older adults with cognitive impairment generally should combine information from multiple sources: patient self-report, searches for causes of pain, observations of the patient’s facial expressions and behaviours, observational pain scales, surrogate reports and a trial of analgesic therapy. The ability to comprehend and use a self-report scale is closely related to the severity of dementia and, in particular, to the communication ability of the patient [39]. During the early to middle stages of dementia, the patient communicative abilities tend to remain sufficient for the verbal communication of pain experience [27, 35, 44–50]. A structured pain interview that includes simple questions related to the presence or absence of pain or discomfort, pain intensity, frequency, location and impact on daily activities is a feasible approach to pain assessment even in the cognitively impaired [51–53]. It may be particularly difficult to identify in severely cognitively impaired individuals as it can manifest itself atypically as agitation, increased confusion and decreased mobility [54, 55]. The American Geriatrics Society described six pain behaviours that must be assessed in older people with dementia that can no longer communicate [40] (Table 22.4). Thirty-five observational pain scales have been developed these last years [56]. However, most of the scales are not feasible in the busy ED environment. This particular setting needs an ease quickly administering pain scale. Probably the most appropriate observational scale is the 5-item ALGOPLUS developed by the ‘French Doloplus collectif’ in France to detect acute pain. The scale has now been translated in six different languages. Pain should be suspected if the score is greater than 2 [57].

Table 22.4

The American Geriatrics Society described six pain behaviours that must be assessed in older patients with dementia that can’t communicate anymore (adapted) [40]

• Facial expressions: slight frown, sad, frightened face, grimacing, wrinkled forehead, closed or tightened eyes, any distorted expression, rapid blinking

• Verbalisations, vocalisations: sighing, moaning, groaning, grunting, chanting, calling out, noisy breathing, asking for help

• Body movements: rigid, tense body posture, guarding, fidgeting, increased pacing, rocking, restricted movement, gait or mobility changes

• Changes in interpersonal interactions: aggressive, combative, resisting care, decreased social interactions, socially inappropriate, disruptive, withdrawn, verbally abusive

• Changes in activity patterns or routines: refusing food, appetite change, increase in rest periods or sleep, changes in rest pattern, sudden cessation of common routines, increased wandering

• Mental status changes: crying or tears, increased confusion, irritability or distress

22.4 Pain Management

22.4.1 General Principles

A patient in the ED can be very anxious about the diagnosis and management, so a clear explanation about the origin of the pain, the nature of analgesia and the expected effects can be reassuring.
Pain management protocols should be available for the management of pain by paramedics before ED presentation.
Depending on the setting and the intensity of pain, some treatment can be administered in the emergency waiting room, following strict protocols.
Early analgesia is very important in preventing delirium—e.g. fascio-iliac block for hip fracture.
Oral forms are usually preferred, but according to expectations and perceptions of the patient, other modes of administration may be justified.
Any possible drug interactions must be detected, especially for treatments likely to be prescribed for several days; there are particular issues about the risks of renal toxicity, e.g. from NSAIDs.
Because of the increased risk of adverse drug events, the principle ‘start low and go slow’ is recommended when dosing analgesics for older adults. Careful titration with frequent reassessment allows for optimal and safe acute pain care.
Pain should be reassessed regularly.
If patients are discharged at home, an action plan should be provided for the continued analgesic management at home (medication dosages and schedules, rescue doses, medical contact).
If opioids are prescribed, precautions and adverse effects should be explained to the patient; attention to the need for co-prescription of anti-emetics and laxatives is necessary.

22.4.2 Treatment

Paracetamol: It is perhaps the safest analgesic in older ED patients. Mechanism is not clearly identified but may inhibit the CNS COX and activate serotonin and cannabinoid systems, which is an analgesic and antipyretic centrally acting devoid of anti-inflammatory effect, unlike NSAIDs [58]. Effective for musculoskeletal pain, paracetamol is recommended by the American Geriatrics Society as a first-line agent for mild ongoing and persistent pain, with increased dosing if pain relief is not satisfactory (up to 3 mg/24 h) before moving onto a stronger alternative [59]. Risks of hepatic toxicity with paracetamol have primarily been observed with long-term use. In case of abuse of alcohol, paracetamol administration should not exceed 2 g daily [60].

NSAIDs: Potentially inappropriate prescription criteria have been devised and validated, called screening tool of older persons’ prescriptions (STOPP) and screening tool to alert to right treatment (START) for detection of potential errors of prescribing commission and omission. According to these criteria, long-term use of NSAID (>3 months) for relief of mild joint pain in osteoarthritis should not be used, and NSAIDs should not be used in patients with history of peptic ulcer disease or gastrointestinal bleeding, unless with concurrent histamine H2 receptor antagonist, proton pump inhibitor or misoprostol (risk of peptic ulcer relapse), with moderate to severe hypertension and finally with heart failure or risk of exacerbation of heart failure [61]. Short-term use of NSAIDs, for example, ibuprofen and naproxen sodium, may be prescribed judiciously in the acute setting for older patients (without contraindications), for example, for an inflammatory process such as acute arthritis. Key issues in the selection of NSAID therapy are cardiovascular risk, nephrotoxicity, drug interactions and gastrointestinal toxicity [62–64]. When NSAIDs are administered, patients should be informed of the risks and warning signs of adverse effects (e.g., decreased urine output, abdominal pain, nausea) and initially started on lowest doses available. Finally, some studies have in recent years questioned the use of NSAIDs in patients with bone or tendon injury due to delayed healing or scarring [65, 66].

Opioids: For older adults with acute moderate to severe pain (4–10 on a 0–10 scale), opioids remain the standard treatment. When starting a treatment in older people, opioids should be prescribed at low doses and titrated to the patient’s response and adverse effects (‘start low, go slow’). However, a careful approach to opioid administration does not mean that time should be wasted as, in patients with severe pain, management should be aggressive and up-titration quite intensive. Changes in drug metabolism, protein binding, distribution and clearance that are associated with ageing may result in a diminished rate of elimination, thus amplifying drug effects and side effects. Careful dosing and administration will limit these risks [67, 68]; for example, because of higher fat to lean body mass ratios, older adults should have starting doses of 25–50% lower than those used in young adults [59]. The decision to use a specific opioid preparation should be based on a combination of the pain characteristics (onset, duration), the product characteristics (pharmacokinetics, pharmacodynamics), the patient’s previous response to opioids (efficacy, tolerability) and above all the patient’s preference for a given preparation. The common adverse effects of opioids are nausea and vomiting, constipation, sedation, confusion and, very rarely, respiratory depression in opioid-naive patients [69]. Opioids commonly used in the ED include codeine, tramadol, morphine, hydromorphone and oxycodone [70–72]; none are ideal and all should be used with caution and careful monitoring. In the ED, oral formulations are usually preferred, with topical treatments being reserved for longer-term pain control. Intravenous morphine should be used cautiously in older people unless patients are already receiving continuous intravenous morphine. The subcutaneous route is preferred because it has less side effects and the advantage to be easily manageable at home or in nursing homes. Occasionally, for unpredictable acute pain, buccal or intranasal fentanyl such as oral transmucosal fentanyl citrate (OFTC) preparations can be used [73–75]. Administration of opioids via the nasal or oral mucosa provides a non-invasive mechanism for immediate drug absorption and rapid onset of pain relief compared with oral dosing [73], although such drugs tend to be more expensive. Furthermore, they should not be used without precaution in opioid-naive patients. Health professionals should anticipate breakthrough pain and prescribe immediate-release formulations of opioids with short half-lives as required, for example, to pre-emptively treat predictable pain during a painful manoeuvre. Although opioid addiction rarely develops in unwell older patients, caution should be exercised when prescribing opioids in patients with known personality disorders or an addiction to alcohol or benzodiazepines.

22.4.3 Topical Use of Analgesics

There are many advantages to using local rather than systemic treatment. The active agent is delivered directly to the affected area, bypassing the systemic circulation, and the dose needed for pain reduction is lower, minimising the risk of side effects [76, 77]. Topical NSAIDs have been shown to be effective in patients with soft tissue injury or related with inflammatory arthritis [78].

22.4.4 Nitrous Oxide-Oxygen Gas Mixture (N₂O/O²)

This can be a valuable tool for the management of acute procedural pain in patients in the ED, as this mixture is easy to use, has a rapid effect and is safe with limited contraindications.

22.4.5 Interventional Techniques

For example, femoral nerve blocks are a feasible and effective option for acute pain due to hip fractures. Usually, this involves administration of a long-acting local anaesthetic (e.g. bupivacaine) under ultrasound guidance [79]. Regional anaesthesia may provide excellent pain relief without exposing the patient to side effects from systemic analgesics. A combination of regional and systemic anaesthesia may also be appropriate (Fig. 22.1, Table 22.5).