Having responded to in-air emergencies, (the latest being earlier this year on an international flight), I can say with some experience that
-the medical equipment on board UA planes has expanded from minimal (to say the least) to quite impressive although they did not have IV fluids available.
-there is MedLink and they are helpful
-I will generally defer to MDs who have ER experience, which happened once
-I have requested an immediate landing in a case of an expected MI
-I have been ignored by UA in the past after the event, but in my latest event was given 20K miles, although I had explicitly asked that they not compensate me.
I am not an ER doc nor do I deal with emergencies other than in my field, but do stay up on the basics of ER medicine. I certainly could not run a code : but I think that if someone needs assistance, one should try and provide it. I think that good Samaritan laws cover these cases, and there is a very strong GS law in the state I practice in.
I don't request feedback either.