There are several doctors here, one of them could pop in and tell us if crumping and crashing are interchangeable. I actually thought "crumping" was the more severe thing to say.
I think “crash” gets used more in the past tense, whereas “crump” gets used maybe equally in both future and past tense? e.g “that patient you signed out to me crumped a couple of hours later” , but also, say when leaving a shift, in the future tense, “the guy in bed 6 is admitted to medicine, but let me tell about him in case he crumps”.