Additional questions - Dementia - End of Life care

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Cause of Death in Dementia (Without Infection)

Question

In the absence of an infection such as pneumonia, what causes the physical death of a person with dementia?

Answer

In the late stages of dementia, death is typically caused by the progressive breakdown of critical bodily functions, rather than a single acute event like infection.

Common Causes of Physical Death in Dementia

  1. Severe Malnutrition and Dehydration
    • As dementia progresses, individuals lose the ability to swallow (dysphagia), leading to aspiration risks, weight loss, and dehydration.
    • This can result in organ failure due to lack of nutrients and hydration.
  2. Failure of the Autonomic Nervous System
    • The autonomic system, which controls involuntary functions like heart rate, blood pressure, and digestion, becomes dysregulated.
    • This can lead to cardiac complications, hypotension, and multi-organ failure.
  3. Immobility and Muscle Wasting
    • Advanced dementia causes loss of motor control, leading to bedsores (pressure ulcers) and muscle atrophy.
    • Bedridden patients may develop deep vein thrombosis (DVT) or pulmonary embolism, which can be fatal.
  4. Respiratory Failure
    • Loss of coordination in breathing and swallowing can lead to aspiration of food or saliva into the lungs, causing silent aspiration pneumonia or respiratory distress.
    • Weak respiratory muscles can contribute to respiratory failure.
  5. Cardiovascular Complications
    • Dementia patients often experience cardiac arrest or heart failure as the brain loses control over critical functions.
    • The combination of malnutrition, dehydration, and circulatory issues can result in organ shutdown.

End-of-Life Considerations

  • Palliative care focuses on comfort, pain management, and quality of life rather than aggressive treatments.
  • Advanced directives and discussions with family members can help in decision-making regarding feeding tubes, hydration, and resuscitation.

References

  • Mitchell, S. L., et al. (2009). The clinical course of advanced dementia. New England Journal of Medicine, 361(16), 1529-1538.
  • O’Brien, J. T., & Thomas, A. (2015). Vascular dementia. The Lancet, 386(10004), 1698-1706.