I went to nursing school while a witness. Did the mental gymnastics around the blood issue. Didn't go to the Red Cross to learn about blood donations (got excused because of religious beliefs) π± Reasoned that I didnt ordered blood and would've interfere with the doctor/patient relationship but I would usually ask other nurses to hang the blood for me.
I held to this policy of mine while even a nurse-practitioner (Certified Nurse-Midwife) until I left the JWs. I was truly free and relieved that I could practice on scientific principles instead of men's mumbo-jumbo.
There is a lot of mental gymnastics that goes on between scientific principles and fundamental religions.