never seen any such patients traveling in train. they have concession's, a doctor to travel with them n also regular medical aid. with such all steps, is it needed to attach another coach with all medical facilities??
such train existed but later it was removed/or still in use, no idea but for such cases, patient;s aren't allowed to travel by train until the doc gives a certificate. if its emergency, flight is arrange n for others a doc also goes with them til the station.