- Fiberoptic bronchoscopy with lavage and bronchial brushing: The subject's mouth and throat are numbed with lidocaine; a sedative may be given for comfort. A thin flexible tube called a bronchoscope is advanced through the nose or mouth into the lung airways to examine the airways. Saline (salt water) is then injected through the bronchoscope into the air passage and then removed by gentle suction. Next, a small brush is passed through the bronchoscope and an area of the airway is brushed to collect some cells for examination.