Pain management: getting it right in elderly patients with dementia or Alzheimer’s disease

23 Jun 2015  |  Print

Pain management: getting it right in elderly patients with dementia or Alzheimer’s disease

Age is a key risk factor for chronic pain: it affects at least 50% of elderly people, and up to 80% of those in residential care.[1] However, despite its high prevalence, pain is severely under-treated in this population.[1]

Dementia adds a further layer of complexity, not least because patients with cognitive impairment often have reduced ability to communicate their pain. Indeed, elderly individuals with dementia are less likely than their cognitively intact contemporaries to report pain.[2]

Could this be because cognitively impaired patients ‘feel less pain’? Does dementia, perhaps, reduce their emotional response to pain? The evidence suggests not

For example, in a recent study, patients with dementia rated pain stimuli similarly as compared with healthy controls, and their facial responses to noxious stimulation were actually significantly increased.[3]Meanwhile, in a functional MRI study of brain responses following mechanical pressure simulation, patients with Alzheimer’s disease showed greater amplitude and duration of pain-related brain activity relative to healthy controls.[4]

Under-treatment of pain

A number of studies have demonstrated that older patients with dementia receive less treatment for pain.

In an analysis of almost 100 elderly people with hip fractures, those with advanced dementia received just one third of the amount of opioid analgesia that cognitively intact contemporaries received.[5] Given that 40% of participants who were able to communicate their pain verbally reported severe or very severe pain, it seems likely that those with impaired communication skills were also experiencing significant pain.[5]

Similarly, in a study of 551 elderly adults in nursing homes in the USA, 80% of cognitively intact residents were receiving pain medications, compared to only 56% of residents with severe cognitive impairment (p<0.001).[6]This occurred despite the number of diagnoses likely to cause pain not varying according cognitive status.

Assessment of pain

There are a variety of reasons why pain may be under-treated in older people with dementia. One reason is the incorrect belief that these individuals are less sensitive to pain, already discussed earlier in this piece. However, there are various other reasons:[1]

  • The idea that pain is a natural and expected part of ageing;
  • Exaggerated fears about the risk of addiction to opioid medications;
  • Resource considerations;
  • Difficulties in detecting and assessing pain in cognitively impaired people.

The last of these may be particularly important, because self-reporting is typically central to pain assessment. While elderly individuals with mild-to-moderate dementia are often able to provide valid self-reports of pain,[7] the same may not be true of those with severe impairment.

This is a significant problem, given that adequate assessment of pain is a prerequisite for adequate treatment of pain.

Many scales have been developed for assessing pain in older patients with dementia, but there is currently no single instrument recommended for broad use in clinical practice. In a systematic review of 12 such tools, the authors concluded that, “none of these assessment scales is convincingly the most appropriate, and therefore preferable, scale for assessing pain in elderly people with dementia.”[8]

A recent multinational initiative supported by the European Cooperation in Science and Technology is attempting to rectify the situation. This initiative, known as Pain in impaired cognition, especially dementia (shortened to PAIC), has aims to develop a comprehensive and internationally agreed toolkit for pain assessment in older patients, particularly those with dementia.[9] Their approach is not to start afresh, but rather to build on existing research in the area, and to develop a consensus about items for a new universal assessment ‘meta-tool’.

In practice, their methodology has involved a three-step process:[9]

  1. Identification of existing observational scales by assessment of review papers published between 2005 and 2012;
  2. Selection of observational scales (12 in total) that meet the eligibility criteria;
  3. Assessment and grouping of items within these scales according to three key categories defined by the American Geriatrics Society – facial expressions, verbalizations/vocalizations and body movements.

The pain assessment items selected based on this process were published in 2014, and are listed in the Table.[9]

Table. Pain assessment by observer ratings in the PAIC tool.[9]

FACIAL EXPRESSIONS VERBALIZATIONS/VOCALIZATIONS BODY MOVEMENTS
Pained expression Using offensive words Freezing
Frowning Using pain-related words Curling up
Narrowing eyes Repeating words Clenching hands
Closing eyes Complaining Resisting care
Raising upper lip Shouting Pushing
Opening mouth Mumbling Guarding
Tightening lips Screaming Rubbing
Clenched teeth Groaning Limping
Empty gaze Crying Restlessness
Seeming disinterested Gasping Pacing
Pale face Sighing
Teary eyed
Looking tense
Looking sad
Looking frightened

The draft meta-tool will require further evaluation to exclude invalid items and refine the included items, but it represents a key first step in creating a universal assessment instrument for use in both clinical and research settings.

Conclusions

Pain is often under-treated in older adults, and this problem is frequently exacerbated in those with dementia. Adequate pain management for these individuals therefore represents one of the most pressing ethical concerns currently facing pain specialists.[1]

Clinicians must be proactive in assessing pain in older patients with cognitive impairment. New tools such as that being developed by PAIC will help to standardize this process, and should lead to improved pain management in these highly vulnerable patients.

References:

  1. 1. Hadjistavropoulos T, Fitzgerald TD, Marchildon GP. Practice guidelines for assessing pain in older persons with dementia residing in long-term care facilities. Physiother Can 2010;62:104-113.
  2. 2. Parmelee PA, Smith B, Katz IR. Pain complaints and cognitive status among elderly institution residents. J Am Geriatr Soc 1993;41:517-522.
  3. . Cole LJ, Farrell MJ, Duff EP, et al. Pain sensitivity and fMRI pain-related brain activity in Alzheimer’s disease. Brain 2006;129(Pt 11):2957=2965.
  4. 4. Morrison RS, Siu AL. A comparison of pain and its treatment in advanced dementia and cognitively intact patients with hip fracture. J Pain Symptom Manage 2000;19:240-248.
  5. 5. Reynolds KS, Hanson LC, DeVellis RF, et al. Disparities in pain management between cognitively intact and cognitively impaired nursing home residents. J Pain Symptom Manage 2008;35:388-396.
  6. 6. Hadjistavropoulos T, Herr K, Turk DC, et al. An interdisciplinary expert consensus statement on assessment of pain in older persons. Clin J Pain 2007;23:S1-S43.
  7. 7. Zwakhalen SM, Hamers JP, Abu-Saad HH, Berger MP. Pain in elderly people with severe dementia: a systematic review of behavioural pain assessment tools. BMC Geriatr 2006;6:3.
  8. 8. Corbett A, Achterberg W, Husebo B, et al. An international road map to improve pain assessment in people with impaired cognition: the development of the Pain Assessment in Impaired Cognition (PAIC) meta-tool. BMC Neurol 2014;14:229.
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  10. RM-0932-V1-0415