Brain death diagnosis in misleading conditions.

The necessity of defining brain death (BD) arose from technological development in medical science. The definition of this concept had practical consequences and opened the way to organ donation from BD patients. Nowadays, the imbalance between the number of organs available for transplantation and the size of the demand is becoming critical. In most laboratories, a BD diagnosis is made according to precise criteria and in a well-defined process. BD diagnosis should be improved, not only to assure the safety and to preserve the human dignity of the patient, but also in order to increase the rate of organ donation. By analysing some epidemiological parameters in BD diagnosis and organ donation, it appears that BD diagnoses can be made more often and more rapidly if one has a reliable, accurate, and safe confirmatory test, especially under misleading conditions (hypothermia, drugs, metabolic disturbances). In our experience, the use of multimodality evoked potentials (MEPs) to confirm a BD diagnosis has many advantages: MEPs can be rapidly performed at the patient's bedside, assess the brain stem as well as the cerebral cortex, and are innocuous for the patient. Moreover, their insensitivity to the aforementioned misleading factors is sufficient to distinguish BD from clinical and EEG states that mimic BD. They give an immediate diagnosis, and no delay is required in BD confirmation if there is sufficient cause to account for BD. MEPs are a safe, accurate, and reliable tool for confirming a BD diagnosis, and their use can improve the organ donation rate while preserving the safety of the patient.