Understanding Drug-Induced Comas: Factors & Recovery

Question
I am not familiar with the proper terminology,so I hope you will understand what I want to know.
What factors does a Dr. need to take into consideration when deciding whether or not to place a client in a drug induced coma?
What is this intended to accomplish for the client?
Is this a last measure when only time is a factor or do clients in this state recover?
Thank you for your time and co-operation.

Answer
Drug induced comas are generally related to head injuries to allow the brain swelling to be reduced and to eliminate the patient being stressed and too active.  While this is occasionally used in terminal patients, most do recover in time. It is not the last measure in most cases. OK?