Importance of Testing for Apnea in the Diagnosis of Brain Death

We tried to evaluate 2 patients both in deep coma and on ventilator, using the Criteria for Brain Death by the Japanese Ministry of Public Welfare. One was a 17 year-old boy with head injury from a traffic accident and the other was a 31 year-old female resuscitated from 20min of cardiac arrest. In the first patient brain death was diagnosed without any problems. In the 2nd patient, during apneic test the PO2 decreased from 330mmHg (FIO2 1.0) to 90mmHg in 2min, so the test had to be discontinued. The rapidity in the decrease of PO2 was, we assume, due to instability of the patinet's respiratory system. This means that everything possible, a prerequisite for the testing of brain death, may not have been carried out. In this paper we discussed the importance of testing for apnea in the diagnosis of brain death in detail.