I got this lecture in med school where the professor/attending told us that the normal respiratory rate for an adult is about 12. And when nurses record 18-20, which they usually do, that actually represents a HIGH respiratory rate.
I just recorded my respiratory rate and it was 12. So I guess he had something there. That or I've OD'd on benzos again. (Kidding!)
He was also right that nurses ALWAYS record the respiratory rate as 18 or 20 (per minute). I have worked at tons of hospitals in several different parts of the country and that seems to be universally true. I'm not even sure what the point is of recording a number, since nobody actually stands there and counts respirations for a minute (or even 15 or 30 seconds). Clearly, this number is always made up.
The one that always baffles me is when they record the respiratory rate as 19. How do they come up with that one?