It means Done Fell Out (of bed) but can also mean Done Fell Over.
It’s from the same school as:
OLFDGB - Old Lady Fall Down Go Boom
TRO - Time Ran Out
DRT - Dead Right There
and
ADS from TMB - Acute Dying Spell from Too Many Birthdays
Sorry, my reading comprehension drops a few levels when I have an 18 month old jumping in my lap.
I think it means a serious injury from a fall. I am not in the med profession, and had to look it up to realise it had originated from there, but I use the term all of the time as a colloquialism.
I actually did think of Dead From Overdose, but it didn’t fit the context - the phrase is used only when there’s some mystery about the cause of death. Done Fell Over seems to fit best.
And on preview: Gfactor, that exact show was on last night - that’s what reminded me to look it up.
So, what EMS and the like use acronyms to sound more mysterious? DFO means nothing more than “Dead, and we have no fucking clue how?” Yeesh. I’m somewhat miffed. I thought it was something really technical.