How is death determined?
Donors after brain death (DBD) are deceased persons whose brain is no longer functional due to a lack of blood flow. The most frequent causes are cerebral haemorrhage, lack of oxygen or a severe craniocerebral trauma.
Brain death is the irreversible cessation of all brain functions (of both the cerebrum and the brain stem). Vital functions such as breathing and the flow of blood can be maintained long enough for organs to be removed through artificial respiration and medication. Brain death is diagnosed in accordance with the guidelines of the Swiss Academy of Medical Sciences (SAMS) by two specialists who do not belong to the transplantation team (compare the guidelines The Determination of Death in the Context of Organ Transplantation, SAMS).
Donors after cardio-circulatory death (DCD) are persons with a terminal prognosis for whom a decision is taken in the ICU to discontinue their medical treatment and let them die according to Swiss Medical Association (FMH) guidelines.
If brain death has not occurred, organ donation may occur after cardio-circulatory death. For patients for whom there are no exclusion criteria for organ donation and who would be expected to experience cardiac and circulatory arrest within 120 minutes of discontinuation of treatment, the question of organ donation may be raised. Any necessary clarifications regarding the organs are carried out and treatment is stopped – usually in the presence of relatives, if they so wish. The breathing hose is thus removed and medications supporting circulation are discontinued, whereupon the dying phase starts.
If cardiac and circulatory arrest occurs within 120 minutes and the electrical activity of the heart has failed, a cardiac ultrasound will also be carried out to establish whether the heart is no longer pumping blood for at least 5 minutes. If this is the case, the death certificate is filled out and witnessed by two specialists in accordance with Swiss Academy of Medical Sciences (SAMS) guidelines. At this point, the deceased person is considered to have experienced both circulatory death and brain death. Subsequently, preparations for organ removal take place and the organs allocated to recipients are removed in the operating theatre under sterile conditions. After removal, the wound is closed. If the process of dying lasts more than 120 minutes, no organs will be removed. Relatives will be informed about the process in advance.
What preparatory medical measures are carried out?
In the case of preparatory and organ-preserving medical measures for donors after brain death (DBD), artificial respiration is continued, medication is administered to maintain circulatory function and hormonal balance, and blood samples are taken for laboratory testing. At the same time, the functionality of individual organs is tested, using, for example, ultrasound or radiology procedures. Taking blood samples and running tests with regard to a possible organ donation only begins after brain death has been diagnosed and the consent to organ donation has been given.