If there’s ever less than 4 patients, then a nurse has to be sent home, not sure exactly what your asking but that’s another way of saying the question if that’s what you needed, if not? Ask me! The only other option I can think of is telling you why they’d be sent home, which would probably be because for every nurse that has to take on patients will eventually run out, and for them to work they’re salary paid job the hospital would be losing money to have to pay the nurse who’s taking less patients, since they work a salary. Rather than paid per patient.