jackruby83

Similar question, what is lobster sauce? It's so thick

The Rh factor is only present on red blood cells, so it matters for blood transfusions, but not organ transplantation.

Singapore Mei fun is my favorite

They way OP describes it pertains to only a subset of deceased donors, called DCD (donation after cardiac death). The are 2 types of death classification in organ donation: brain death (DBD) and cardiac (heart) death. In brain death, the donor is legally dead and goes to the OR for procurement once all organs are allocated. There is no delay after that. Cardiac death donors do not meet brain death criteria but will never recover, and life will need to rely on machine support. Many families decide to withdraw care and allow them to pass peacefully. If the donor dies within a prespecified amount of time, then procurement can take place. Otherwise, if too much time lapses, damage from lack of oxygen can occur.

Other reasons may include recipient issues (last minute discovery that the recipient has some reason to delay, infection /cancer/heart issues/etc) or donor issues (maybe donor is found to have infection, cancer, fat around organ, maybe biopsy is done which shows scarring, etc.).

This isn't entirely correct. Brain dead donors are in fact legally dead and do not require any time to allow them to "die completely". Their time of death is declared when brain death is declared. Their bodies are kept artificially perfused by machines (inappropriately called "life support") until all the organ are allocated - then they go to OR for procurement.

There is a subset of donors that are not brain dead (~15% kidney donors in the US), but have suffered a devastating brain injury. They will never be who they were, and will not be able to "live" without machine assistance. These donors are the ones that many families decide to withdraw care, and allow for donation. In these cases, machine support is withdrawn and the patients dies on their own. Then, organ procurement can take place once death has been declared, if the patient dies within a defined window.