Playing God: Who should make end-of-life decisions?

When a critically ill patient is admitted into a hospital there are some circumstances where the patient is just to ill to continue on living as they are.

They are on what’s called life support, a device that keeps the patient on life sustaining medication or oxygen in order to keep them alive.

Without this the person would die of their disease or natural cause.The question is whose decision is it to permit weather or not that person lives; is it the doctor or the family?

Who gets the say on pulling the plug or letting that person survive? Also is it moral to pull the plug or can it be considered murder?