Twice, as ride-along which was nice to be allowed. First time when we brought our 7 month old DS with a bad hernia to a small regional hospital during a summer long weekend. After hours of not being able to do much for him, they finally referred him to a larger hospital 2 hours away. I rode along, the poor little one finally slept after hours of screaming, and the attendants were wonderful. My poor DH drove behind us not knowing what the situation was.
Second time included ambulance, helicopter and then jet-ambulance from our northern town to Vancouver for my DH with heart issues. He was flown down for emergency bypass surgery. I was very lucky to be allowed to go as passenger, since they had no other patients. It was a blur for him, and I admit watching the heart monitor for the whole 3 hour process, but the air ambulance staff were wonderful, and I was impressed with the efficiency of our medial system.
Both incidents turned out well, thank goodness.