The extubation procedure consists of the removal of the endotracheal tube when it is no longer required. The literature reports two methods of extubation: the named traditional method (with suction and without positive pressure in the airways) and the positive pressure method. Laboratory studies suggest extubation at positive pressure because it reduces the volume of secretions filtered into the distal airway. Prior to apply it into clinical practice the investigators of this study consider is a priority to guarantee the safety of the positive pressure extubation method in terms of presence of complications.