Clinical diagnostic of brain death requires a non-reactive coma, absence of brain stem reflex, and absence of spontaneous breathing. The confirmation of absence of spontaneous breathing is established the apnea test (according to the American Academy of Neurology's Guidelines). However this test may lead to complications (acute hypoxemia, ventilatory and cardiocirculatory disorders) and reduces significantly the number of lung transplants. Some data suggest modifying the apnea test : replace the ventilator switching off with continuous positive airway pressure (CPAP) use. These studies showed that this alternative method (CPAP) increased the level of lung harvest but they were not sufficient because these studies were monocentric with little patients,. That why the aim of the present study is to compare the standard strategy and CPAP strategy with a prospective, multicenter,cluster trial; each center will use the method of apnea test which it uses usually.