The concept of death has long fascinated humankind. The determination of the final moment of life and the subsequent entry into the irreversible process of dying has been charged with both religious, legal, and practical implications. What was once a relatively straightforward determination, that is, death occurred when breathing and blood circulation ceased, has taken on additional complexity over the last several decades. Technology has allowed us in many cases to artificially perform the functions of respiration and circulation for the human organism. Because these traditional criteria were no longer necessary component parts in the determination of death, new criteria were necessary to allow physicians to make that pronouncement. The concept of “brain death” has been developed to fulfill this need and to assist us in deciding when the patient has ceased being an individual, but rather has irreparably become a physiologic preparation devoid of any of the personality that once made it a unique specimen.

Death, probably more than any other area of medicine, brings forth the most intensely personal aspects of a physician's upbringing, religious beliefs, and deepest personal convictions. Although often allowing the individual physician to function in a difficult area, these feelings may also cloud decision-making and make differences of opinion in this area more based on belief than science. This article discusses the current thinking in the evaluation of the patient in making the diagnosis of brain death.