How effective is an induced coma for treating cardiac arrest?

Cardiac arrest: When you have cardiac arrest you are dead. Induced coma is done only when you are alive. As such it isn't a treatment for cardiac arrest. If a patient happens to be resuscitated from cardiac arrest, inducing coma can be a consideration to hope the brain will recover with less metabolic demand on it. It isn't done regularly. We are considering if cooling post arrest survival is as useful as thought