Key learning points

  • COPD and dementia are both systemic conditions which share risk factors and frequently co-exist
  • Issues with medication can also make the conditions difficult to co-manage
  • With some support, compliance and self-management is possible

As GPs we will all be familiar with the challenge of managing respiratory conditions in patients with memory problems. That the two co-exist so frequently is not simply due to both being common conditions that become more prevalent with age. There is a much more subtle and complex link between them, with one study showing that cognitive impairment is present in 50% of patients with COPD compared with 7% of controls.1

In one sense this link is not surprising. Smoking, the main risk factor for COPD, is also a major risk for both Alzheimer’s disease and vascular dementia. Other more subtle factors are at play: lung and brain disorders are increasingly viewed as systemic conditions with inflammatory and metabolic elements, again making many risk factors common to both.2 

Mid-life chronic lung disease has been found to be associated with a 29–58% higher risk of developing cognitive problems in both smokers and non-smokers, strengthening the idea that inflammation, oxidative stress, and abnormal tissue oxygenation play a part in damaging both lungs and brain.3 This view is strengthened by the finding that other comorbidities such as cardiovascular diseases, osteoporosis and diabetes were commoner in COPD, again independent of smoking and other traditional risk factors.

With well-established COPD, more obvious factors come into play, with hypoxia and hypercapnia having a direct effect on worsening cognitive function. Drug issues can also make the combination of conditions difficult to manage: we have long known that anticholinergics worsen cognitive function, but the anticholinesterase inhibitors (AChEIs) such as donepezil used in Alzheimer’s disease, can cause exacerbations of COPD. In one small study, 19% of those using AChEIs experienced exacerbations over 90 days compared with 7% in non-users, resulting in increased hospital admissions.5

The other obvious issue in patients with both conditions is compliance, and the ability to self-manage exacerbations. This is not simply a memory issue: dementia affects cognitive ability as well as memory, so that tasks such as using inhalers may be more challenging especially as the patient becomes hypoxic.6 With dementia, a lack of awareness of disease (anosognosia) is a frequent concomitant, so that patients may be unaware that they are running into difficulties with their breathing.

Given these challenges, how are we to manage them? Here the evidence base is more sketchy, and sometimes states the obvious. ‘Prescribing a simple regimen and recruiting a family member to supervise medication may be the keys to compliance7 is typical. However, there are some useful resources from those with practical experience in the field and it is worth looking at the presentations listed.7,8

Overall, the best advice from both personal and expert experience is:

  • When COPD is diagnosed, perform a simple memory test (e.g. mini-cog) as the likelihood of cognitive impairment is high
  • Keep medication simple, and deprescribe where possible. One-daily dosing (e.g. doxycycline over amoxicillin for rescue medication and steroids in a single daily dose) will be more successful
  • Recruit carers, check how often they visit and get them to supervise medication where possible
  • Use spacers, check inhaler technique frequently. Patients with early dementia can still learn, but will need more repetition
  • Pulmonary rehabilitation remains one of the most useful interventions, but may need to be tailored to that patient
  • Use visual cues to prompt compliance. Digital technology can be useful, but a large notice on the fridge is often better!
  • Use dosette boxes and get carers to record that medication has been taken to reduce confusion
  • Check for mental capacity: if they have capacity, they are allowed to make unwise decisions; if not, a ‘best interests’ decision can be made

In conclusion: COPD and dementia are both systemic conditions which share risk factors and frequently co-exist. Dementia can make compliance and recognition of deterioration difficult. However, people with mild to moderate dementia can still learn; patience, kindness, and employing simple adjustments can make a huge difference to people’s lives.

Dr Peter Bagshaw is a GP and clinical lead for mental health and dementia, Somerset CCG

This project was initiated and funded by Teva Respiratory. Teva have had no influence over content. Topics and content have been selected and written by independent experts.

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