A 68-year-old female with a history of laryngeal papillomatosis and previous difficult intubation is scheduled for elective endoscopic laser ablation of recurrent papillomas. The anesthesiologist plans an awake fiberoptic intubation. After topical anesthesia and mild sedation (dexmedetomidine), the fiberscope is advanced but encounters significant secretions and blood obscuring the view at the level of the false vocal cords. The patient begins to cough and gag. What is the most appropriate immediate management?