Emergency rooms save people every day but that doesn’t mean mistakes don’t happen. You learn this quickly on the EMS side of the business.
One day we brought in a possible heart attack victim. He was unconscious, but had a rhythm. After we left him in the treatment room still very much alive, we went to restock the drug box, replacing the items we had used on the call. Walking back toward the front desk, I passed the treatment room again, and saw the staff doing CPR on our victim. I watched for a minute or two and then noticed one of the leads to the heart monitor had become disconnected from the pasty on his chest. Walking into the room, I tapped one of the nurses on the shoulder and pointed out the discrepancy.
“Oops,” the nurse responded as she reconnected the lead. They stopped compressions to check the rhythm and he did indeed have one. One of the first things they teach you when becoming an EMT is that doing compressions on someone who has a heartbeat is a bad thing.