1. Complications : Investigators will register the events related to an agitation episode or delirium and classify them in three groups. The three groups are determined by the potential life threatening character of the event. One event can be considered as severe i.e. really life threatening (self extubation, ventilator disconnection, central catheter removal, chest tube removal, trauma, falling from bed), moderate (removal of nasogastric tube, peripheral venous or arterial catheter) or mild i.e. not life threatening (contortion of the patient in his bed, patient's aggressiveness toward the staff, urethral catheter removal, electrode or saturation monitoring removal).