The most important thing is to lie or sit still.  Let the doctor know if you are having any chest pain or shortness of breath.  After the procedure, you will probably have to lie quietly and breath oxygen for a while.  You can take off the bandage 24 hours after the procedure and wash the area.  Inform the physician if you have a hard time breathing, or develop a new fever or chills, or redness at the puncture site.