What is the ruling on refusing the request of Muslim doctors not to provide the sick mother with a ventilator in the future, under the pretext of their despair of her recovery?

It is not permissible to remove or withhold a ventilator from a patient unless it is definitively determined that they are in the status of deceased. This occurs when all brain functions have completely ceased, or when the heart and breathing have irreversibly stopped. Death is legally pronounced when breathing and heartbeat have completely ceased after the removal of the machines. What is known as "mercy killing" by withholding medication or other means is not permissible, as it is a forbidden form of killing.