Here in the greater Cincinnati region it is very common to have paramedic Captains (and Lieutenants). Although they typically serve as the officer-in-charge, I have witnessed many times where they put there paramedic skills to use.
The Cincinnati Fire Division itself has 12 paramedic engines (out of a total of 26 engines). Staffing on a Cincinnati Paramedic Engine Company is a total of 4 personnel; a Captain or Lieutenant and one firefighter serving as the paramedics, while 2 EMT-Basic's make up the remainder.