Nic tells Conrad to get a costume for the party and she sees him as a character from the Marvel Universe. This is a nod to Emily VanCamp's role as Sharon Carter, Peggy Carter's niece in the MCU.
TXA is short for Tranexamic Acid. It is used to treat extreme blood loss.
The main patient for the Halloween set episode is called Laurie, which is the same name as the protagonist in the Halloween franchise.