During this drive, the speed limit mattered very little to me, and I drove as fast as I possibly could.
Whether this was "right" or "wrong" isn't something that crossed my mind at the time. When one's own life (or the life of a loved one) is on the line, people have a tendency to do things that don't make sense to an outside observer.
Luckily for us, we arrived at the hospital without further incident, and my father was quickly cared for. I didn't time the trip, but I imagine it was only marginally faster than driving at the speed limit, as my vehicle at the time wasn't particularly fast.