You should be more interested in the company or service you work for. In Texas because of limited numbers of EMT-b's, I's, and paramedics. The department of state health doesnt exactly have a scope of practice. It's all up to your medical director you practice under. You have places such as midland,TX who run with basically ACLS drugs along with the basics. Very very limited. In northern Houston you have medics that are initiating/completing clearing c-spine, preparing a pt for hypothermic therapies, administering thrombolytics for MI and DVT patients. You also have small towns such as presidio who have EMT basics doing chest decompressions, IV's, drug administration, EKG interpretations. With medics performing chest tubes, foley catheters, and use of 50 narcotic and 200 other drugs on their box. And to all who work in Texas please correct me if I'm wrong if this information is misleading. Simply put with a doctor who will administer the order and stand behind you. Their is nothing you cannot do.
I would like to add that in those areas where you do more than your trained for by NREMT standards you will generally have extensive training into each procedure you learn. In some places I've known of services that require you to sit in front of your medical director and complete a oral and psyco motor exam prior to being signed off.