Ed Asner, who plays "Hospital Patient" is no stranger to DC series. He has voiced Roland Daggett on "Batman: The Animated Series", Granny Goodness on "Superman: The Animated Series", "Justice League Unlimited" and "Superman/Batman: Apocalypse", Kent Nelson on "Young Justice" and Perry White on "All Star Superman".
During the opening scene of this episode Linda Scott's "I've told every little star" is played to represent that the scene takes place in 60s. Previously this song was used in David Lynch's Mulholland Dr. (2001)