We frequently push IV meds through the CVP port, then flush and zero, Sometimes that is the ONLY place we have to run something "extra". Sometimes we have femoral A lines that have extended tubing on it to run to the trancducer on the opposite side of the bed with a port to draw from laying over the patients belly that could EASILY be confused with a CVP port by a nurse that may be in a hurry or not as concientious. And since I prefer safer is always better, I check and relable all of my lines at the beginning of my shift. We have had a subclvian A line recently (first one I've seen, was really cool), but the port could have easily been confused with a CVP port.