Leading practices and guidelines for deceased donation can be found here
Flow is not perfusion, and perfusion is not function: ancillary testing for the diagnosis of brain death Guillaume Plourde MD, PhD, FRCPC, Joel Neves Briard MD, Sam D. Shemie MD, Jai Jai Shiva Shankar MD, DM, MSc, FRCPC & Michaël Chassé MD, PhD, FRCPC Canadian Journal of Anesthesia/Journal canadien d'anesthésie volume 68, pages953–961 (2021)
Leading practices and guidelines for organ donation and transplantation along with accompanying peer reviewed publication can be found here