You may consider adding wording similar to the below to your advance directive ( you DO have one, right ?) if you are concerned about being kept alive with severe cognitive impairment.
If I develop dementia or incur a stroke or other neuro/muscular or other disorder to the extent I am not oriented to time and place, or it substantially affects my ability to live independently and am also judged by physician(s) to not be competent to refuse medical treatments on my own, I want no further medical treatments to treat or prevent any potentially lethal outcomes. Examples of such treatments include, but are not limited to:
1. Surgeries for conditions such as appendicitis, obstructed bowel, aortic or cerebral artery aneurysm, etc.
2. Blood transfusion
3. Antibiotics for serious infections
4. IV fluids or agents to treat shock from hemorrhage or sepsis, etc.
5. Steroids to reduce brain swelling or pericarditis, etc.
6. immunizations designed to prevent the annual flu or other conditions.
Withholding these treatments may cause more discomfort and suffering – such as pain, anxiety, confusion, nausea, depression, so I ask my physician(s) to use liberal dosages of sedative and pain medications including narcotics even if they may hasten my death.
If I am unable to feed myself, I do not want to be hand-fed, and I do not want artificial hydration or nutrition.
I am not afraid of death and am much more distressed about living in a twilight haze, being confused all the time, being bedridden or unable to get out of bed, incontinent of bowel or bladder, requiring round-the-clock care, or otherwise being a dependent burden to my family and an expense to them and society.
If my mental and/or physical condition prevents me from living a reasonably independent life, even if I can breathe and drink and eat independently, I desire that nature be allowed to take its course so that any potentially lethal disorder I encounter is allowed to assist me in my final exit.
Signature _________________________________ Date __________________________