I called my health unit today and they put me through to a lady named Shelly, who, it turns out, is the manager of the ER department. She assured me that this is NOT normal procedure and she would be talking to the nurse in question. When I asked her if it was normal for there not to be a doctor there she said "Absolutely not," and explained that he might have been taking a nap somewhere or was on another floor. Technically he's working, but that's his "break time". She did say, however, that if it was a case like mine where there was potential for something very serious to happen, he should have been notified.
She told me that as an athsmatic herself, she understood how scary it can be, and assured me again that this would be taken very seriously. So we'll see what happens.