The Limits of Advance Directives in Maintaining Autonomy in Patients with Advanced Dementia.

As dementia becomes more prevalent in the aging population, clinicians increasingly face the challenge of caring for patients who had told family members that they preferred death to life with advanced dementia. Advance directives can guide management, but usually are inadequate in caring for patients with advanced dementia. The "now" patient has very different sensibilities than the "then" patient who had expressed preferences for terminal care before dementia severely impaired cognition and executive function. Clinicians lack clear means of following a patient's directive to die rather than to live with advanced dementia. Withholding life-sustaining oral feeding or fluids is ethically problematic. Controversies remain over precedent autonomy as the justification for advance dementia directives, and the consequent legal, ethical, and practical issues clinicians face, particularly involving feeding.