If the doctor/surgeon's kid had an injury and was bleeding out..... only one substance will save them, blood. We have no synthetic blood and we die without it. Want to try to make up a reason they would deny it for them, or themselves?
Blood is not some magical substance. It is water and minerals, it has red blood cells which are nothing more than iron and proteins.Blood is screened and treated so the risk of infection is very low.
Blood is used in two ways, one to improve symptoms or in preperation for blood loss dueing a procedure.
The other is when someone has bled and who will die without it.
Some can get away with saying no to less vital indications, but not for the life threatening.
You need to be more careful in taking what you hear without question.
If blood scares you, do some reading about what it is made of and note that every human is full of it and dies without it and even gets very sick if some is lost. There are risks with medical interventions, there are even risks giving someone oxygen, giving fluids even.... but water and air are not dangerous.
Would some doctors say no to blood if it was offered to them in a non life threatening medicsl scenario......maybe, likely, yes....... bit that is wholly different to life saving blood required after a car crash, or a heavy post birth bleed or if you have a bleeding disorder etc etc etc... then only blood will do.