Why iinduced coma if brain damage?

Coma for high ICP: In patients with traumatic brain injury (usually the result of a motor vehicle collision) the intracranial pressure (icp) often increases to a dangerously high level. These patients often need to be ona breathing machine and be sedated to a deep level. Sometimes they need to be under Pentobarbital coma in an effort to keep the icp within an acceptable range until the brain edema (swelling) drops.

Brain protection: If a brain is swollen and fragile, sometimes a coma is induced to prevent the pressure inside the head from becoming too high and causing additional damage.