I had this same question regarding the heart cath lab because my cath lab is a high risk one. We do many high risk procedures. Many of our patients fly to us very unstable. We stabalize them, do the procedure, place a balloon pump, and do all of the crititcal care procedures that an ER nurse or MCCU, ICU, nurse etc would perform. However, we are not considered critical care nurses. The reason that I understand is that all cath labs are different. This sounds funny when you think about it, but there are cath labs that are only diagnostic. They only do heart caths. Therefore, if someone says they have experience in the cath lab, which one was it? A high risk cath lab or a diagnostic? It could be the same for an ED. I say that becasue we own two hospitals with different types of ED's. One is in an area that has a younger population, so the patients coming in are more likely to be young adults, children and infants. If they get a heart attack victim, they stablize and send them to the cath lab at the other campus. The campus with the cath lab caters to the older generation (location is partly the reason, the other is due to our specialty). We recieve many geriatric and older adults along with middle age adults with possible heart attacks, chest pain, etc. It makes alot of sense if you look at the broad picture. Yes, we do critical care procedures in the ED and cath lab areas, but not all hospitals ED or cath lab are the same, so there is a difference in the rating of the critical care nurse. Like I said, this is the way it was explained to me. It is great experience and I think that if you want to transfer or switch jobs, you could list the skills that you have from working in your current ER position.