Researchers and medical professionals have spent years perfecting machines that can be used to sustain life. We have amazing medical technology; artificial breathing machines, tubes that transport food or fluid, and machines that can sometimes restart a stopped heart. Clearly, these devices can provide short-term help to people who have suffered from a traumatic injury or illness by giving their body time to recover.
Life-sustaining machines can also be utilized well after medical professionals determine that there is no brain functioning occurring and that a person's medical situation is not likely to improve or change at any point in the future. Essentially, we can be kept alive solely by machines on an indefinite basis (or for very long periods of time), without any reasonable chance of our ever regaining the ability to breathe, eat or act independently.
Due to ethical and legal concerns, hospitals have established very clear policies about the use of heroic measures. In the past, medical professionals have been sued by families for allowing a patient to die when the family believed the hospital could have prevented the death if only they had continued to provide care. Therefore, hospitals tend to use all heroic measures available to them unless there is a healthcare directive in place, or the family is willing to sign a document stating that they do not want such measures used and that they are releasing the hospital from any liability if the patient dies.
If the dying person you love has not already filled out a health care directive, urge them to do so as part of their dying "business." As mentioned previously, it is critical that a dying person make his or her wishes known in advance of their becoming incapacitated. An advance directive can reduce the possibility of family members having to make medical decisions without guidance or directions. Choosing a health care proxy by filling out a Durable Power of Attorney for Health Care can also avoid a situation where well-meaning family members choose to begin or continue heroic measures that a person would not want.