Depends upon what you mean.
Euthanasia is a rather broad term that can mean many different things. There is voluntary and involuntary euthanasia, passive and active euthanasia, medical and non-medical euthanasia.
Passive voluntary medical euthanasia is very common. Active voluntary medical euthanasia is in legally held in several states.
Terminal weans and palliative sedation (although the goal is not death but rather a common result) are commonly used interventions in many states.
I've actively participated in many and it is not a pleasant thing, no matter how much I liked the patient. I like my current work setting better.