It might seem like a basic question, but when it comes to coding, the rub is always in the chart note.
Our organization always looks at ventilator dependency as only applicable if the provider documents it such. The chart must state ventilator dependency in order to apply this code, and is usually only used for a more chronic situation (ie. not for short term ventilator dependency). I would also refer to the Chapter 21 guidelines in the ICD-10 book, which may help you as well. I am not seeing a lot of Coding Clinics which could help you here, other than perhaps the 2015, Q1; which doesn't answer your question directly either.
I am sure someone would disagree with me, however we have seen plenty of provider claim errors in RADVs come back to us based on miscoding Z99.11.
Hope this is a little bit helpful, even though I didn't really fully answer your questions.