A more thorough explanation:

Life-prolonging procedure

A life-prolonging procedure, also known as a life-sustaining procedure or treatment, is a medical treatment that is used to extend or maintain a person's life without curing the underlying medical condition. Examples of life-prolonging procedures include cardiopulmonary resuscitation (CPR), mechanical ventilation, and hemodialysis.

Life-prolonging procedures are treatments that are used to keep a person alive when their body is not functioning properly. These treatments do not cure the underlying medical condition, but instead, they help to keep the person alive for as long as possible. For example, CPR is used to restart a person's heart when it has stopped beating, while mechanical ventilation is used to help a person breathe when they are unable to do so on their own. Hemodialysis is used to filter a person's blood when their kidneys are not functioning properly. These procedures are used to prolong a person's life, but they do not cure the underlying medical condition.