Death before Organ Donation
There are two legal definitions of death- cardiopulmonary death and brain death. Cardiopulmonary death is the irreversible loss of function of the heart and lungs. Brain death is the irreversible loss of function of the brain and brain stem that occurs when blood flow to the brain has permanently ceased.
Donation after Brain Death
When a patient has a brain injury that is not survivable, a physician performs a series of tests to determine if brain death has occurred. When brain death occurs there is a loss of life-sustaining reflexes such as the ability to breath, gag, or respond to pain. Brain death can be confusing for families who are confronted with the sudden death a loved one. A brain dead person on a ventilator can feel warm to the touch and can look "alive". The heart is still beating and the ventilator is pushing oxygen and air into the lungs making the person’s chest rise and fall. Patients who are brain dead can be maintained on ventilator support for a short period of time. Regardless of ventilator support, organ failure will occur. This is why time is critical in the donation process.This image of the brain shows blood flow inside the brain. The animation shows a "simulation" of how blood flow to the brain ends or is shut off as the brain swells in a brain injured patient. The absence of blood flow will lead to brain death, a legal and medical determination of death.
Source: www.organtransplants.org Used with permission.