Organ donation provides life-saving transplants and relies on three distinct classifications of donors based on their medical status. This categorization is necessary because the donor’s condition directly impacts which organs and tissues can be safely recovered and transplanted. The system distinguishes between living donors and deceased donors, with the latter group further divided by the medical criteria used to declare death. Understanding these three statuses is key to comprehending the logistics of transplantation.
Living Donor Status
A living donor voluntarily chooses to donate an organ or a portion of an organ while healthy. This donation is often preferred because it allows for scheduled surgery, potentially improving the outcome and eliminating the recipient’s wait on the national registry. Common donations include one kidney or a segment of the liver, as these organs can sustain function with partial loss or regenerate over time. Living donors can also donate tissues such as bone marrow and blood-forming cells.
The decision to become a living donor requires a rigorous medical and psychological evaluation to ensure safety and informed consent. This assessment includes physical examinations, compatibility blood tests, and screenings for disqualifying conditions like diabetes or active cancer. A psychosocial evaluation ensures the decision is voluntary and free from external pressure or financial coercion, as the sale of organs is illegal. The remaining organ or segment must sustain the donor’s long-term health, and recovery typically lasts six to eight weeks.
Deceased Donors Following Brain Death
Donation after Brain Death (DBD) involves a patient with an irreversible loss of all functions of the entire brain, including the brain stem, which is legally recognized as death. This condition usually results from catastrophic events like a severe stroke or traumatic head injury, where the brain is deprived of oxygen and blood flow. Although the individual is deceased, mechanical ventilation and medication temporarily maintain heart function and circulation.
The continued circulation of oxygenated blood preserves the viability of most major organs for transplantation. Since the organs remain perfused, the surgical team can recover the heart, lungs, liver, pancreas, kidneys, intestines, and various tissues. Hospital physicians, who are independent of the transplant team, document the time of death once neurological criteria are met. This status provides the best chance for organ recovery due to minimal damage from lack of blood flow.
Deceased Donors Following Circulatory Death
Donation after Circulatory Death (DCD) occurs when a patient suffers irreversible cessation of heart and respiratory function, the traditional criteria for death. This pathway is used when a patient has a severe, non-survivable injury but does not meet brain death criteria, and the family decides to withdraw life-sustaining treatments. Organ recovery begins only after the heart has permanently stopped beating, followed by a mandated observation period.
This observation period, typically two to five minutes after the heart stops, ensures the cessation of circulation is irreversible before death is declared. The time between withdrawing life support and starting cold perfusion is called warm ischemia time, during which organs are deprived of oxygen and sustain damage. Because of this ischemia, DCD organs, such as kidneys, liver, and lungs, are more susceptible to delayed function after transplantation compared to DBD organs.