Dr. Dulmacher is a likely reference to the Batman villain "the Dollmaker," a serial killer that specializes in body harvesting and transplants. This especially seems true as Dulmacher tells Fish that he threw in a new face for his kidney patient, a service the Dollmaker provided for the Joker in Detective Comics #1 (September 2011).
Bruce reads to Alfred: "I looked at the stars, and considered how awful it would be for a man to turn his face up to them as he froze to death, and see no help or pity in all the glittering multitude." It is from Great Expectations by Charles Dickens.
The newspaper article shown early in the episode was written by Christina Barker. Barker is listed as Additional Crew on the series. This is the first time the show uses a crew member's name in such a way.
Unlike the many other actors who went from DC to Marvel, Colm Feore (Dr Dulmacher) went from Marvel to DC. He played King Laufey in Thor (2011).