This episode is dedicated in "Loving Memory to Teddy Ebersol." The 14-year-old Edward "Teddy" Ebersol was killed in a charter plane crash on November 28, 2004. His mother Susan Saint James is the aunt of Christa Miller (Jordan Sullivan). Jordan is Dr Perry Cox's wife and Jack Cox's mother.
J.D. tells Turk that Jerry the patient has Cotard's syndrome. According to Wikipedia, "Cotard's delusion, also known as walking corpse syndrome or Cotard's syndrome, is a rare mental disorder in which the affected person holds the delusional belief that they are dead, do not exist, are putrefying, or have lost their blood or internal organs."
J.D. and Turk attempt to goad Billy into naming the different components of the Lucky Charms cereal to prove he is Irish. However, Lucky Charms is an American cereal and is not widely sold in Ireland, outside of shops specializing in foreign foods.
Dr. Kelso is from Monroeville, PA. Monroeville is a real town near the city of Pittsburgh.