- Patients with a major endobronchial lesion in the segmental, lobar, or mainstem bronchus with complete obstruction of the airway may be eligible for bronchoscopic injection provided there is no evidence of respiratory failure (defined as SaO2 at least 90% on room air, PCO2 less than, or equal to 45 mm Hg, or FEV1 greater than 1.0L)