The question of whether a person must be brain dead to donate organs is a common source of confusion. While brain death has long been associated with deceased organ donation, it is not the only pathway available. Modern medicine and standardized legal criteria recognize two distinct ways in which death is declared that allow for organ donation. The path taken affects which organs may be transplanted and the specific medical procedures involved.
Defining Death for Organ Donation
The medical and legal frameworks for organ donation recognize two separate, but equally final, definitions of death. The difference between the two is the physiological system used to determine the moment of death. The first criterion is the irreversible cessation of all functions of the entire brain, including the brainstem, termed Death by Neurological Criteria. The second is the irreversible cessation of circulatory and respiratory functions, known as Death by Circulatory Criteria. Both definitions are legally accepted under the Uniform Determination of Death Act, which provides a consistent standard across jurisdictions.
Donation Following Brain Death
Organ donation following Death by Neurological Criteria, referred to as Donation after Brain Death (DBD), remains the most frequent pathway for deceased donation. Declaring death requires rigorous clinical examinations and diagnostic tests to confirm the permanent loss of all brain function. Testing involves checking for the absence of specific brainstem reflexes, such as the pupillary light reflex and the gag reflex. A confirmatory apnea test is also performed to ensure the patient cannot breathe independently. Because the heart and lungs are maintained artificially by a ventilator, the organs remain perfused with oxygenated blood until recovery, keeping them in the best condition for transplantation.
Donation Following Circulatory Death
When a patient has suffered a catastrophic, non-survivable injury but does not meet the criteria for brain death, donation may still be possible through the Donation after Circulatory Death (DCD) pathway. This process occurs after the medical team and family decide to withdraw life-sustaining support, such as a ventilator, and the patient is moved to a designated area. Death is declared only after the irreversible cessation of heart and lung function. This requires observing a sustained period of no pulse and no heartbeat, typically two to five minutes, to ensure no auto-resuscitation occurs. Since circulation has stopped, the organs are deprived of oxygen, requiring rapid recovery to limit warm ischemia and preserve viability.
Consent and Protecting the Donor
Regardless of whether death is declared by neurological or circulatory criteria, the donation process cannot begin without legal authorization. Authorization is typically established through the individual’s prior registration on a state or national donor registry. If the patient has not registered, the legal next-of-kin must provide informed consent for donation to proceed. A fundamental safeguard is the mandatory separation of responsibilities between medical teams. The physicians responsible for declaring the death of the patient must be entirely distinct from the surgeons and staff involved in the organ recovery and transplantation process, ensuring no conflict of interest.