OK, I dug a little more. You might want to look at NEC 517.32(A) first.
From NFPA 101, I found this:
7.8.1.1* Illumination of means of egress shall be provided in accordance with Section 7.8 for every building and structure where required in Chapter 11 through Chapter 42. For the purposes of this requirement, exit access shall include only designated stairs, aisles, corridors, ramps, escalators, and passageways leading to an exit. For the purposes of this requirement, exit discharge shall include only designated stairs, aisles, corridors, ramps, escalators, walkways, and exit passageways leading to a public way.
Here are two helpful definitions out of 101:
3.3.62* Exit. That portion of a means of egress that is separated from all other spaces of a building or structure by construction or equipment as required to provide a protected way of travel to the exit discharge.
3.3.63 Exit Access. That portion of a means of egress that leads to an exit.
I know most patient rooms would have lights backed up by an emergency generator. But I think those lights can be switched off. This is only my opinion, but I don't see anything that requires 24 hour egress lighting in a patient room.
Steve