There is a short article in NEJM about dealing with racist patients:
https://www.nejm.org/doi/full/10.1056/NEJMp1514939
There are numerous other articles and opinions on the issue, such as:
https://www.medpagetoday.com/hospitalbasedmedicine/generalhospitalpractice/72169
https://www.statnews.com/2017/06/12/racism-bias-patients-doctors/
https://www.aafp.org/news/blogs/freshperspectives/entry/20170821fp-race.html
https://www.washingtonpost.com/opinions/racist-patients-often-leave-doctors-at-a-loss/2017/10/19/9e9a2c46-9d55-11e7-9c8d-cf053ff30921_story.html
https://www.thedailybeast.com/how-i-deal-with-racist-patients