How is the anticipated difficult intubation approached?
Anticipated difficult intubations with proven or sus-pected difficult mask ventilation are best approached with the patient awake and spontaneously breathing. Proper preparation of the airway before instrumentation is criti-cal. Preparation begins approximately 1 hour before arrival in the operating room. At that time, antisialagogues are administered as premedication. Their use is intended to desiccate the mucosa before administration of topical local anesthetics. An intervening layer of secretions acts as a physical barrier preventing contact between local anesthetic and mucosa. Without direct contact of the two, inadequate airway anesthesia results and predisposes the patient to coughing, gagging, and withdrawal. Furthermore, copious secretions impair the view through flexible fiberoptic laryngoscopes. Depending on the degree of pre-existing airway compromise, preoperative sedation may be contraindicated.
After adequate antisialagogue effect, airway anesthesia is most easily achieved by nebulizing 4 mL of 4% lidocaine. Another equally effective option is to atomize the same solution. Superior laryngeal nerve blocks and transtracheal nerve blocks are sometimes required.
If the nasal approach is planned, the risk of epistaxis can be minimized with topical application of 0.5% phenyle-phrine, 4% cocaine, or 0.05% oxymetazoline (Afrin). In the absence of local nasal pathology, flexible fiberoptic nasal tracheal intubation is generally less difficult than the oral route.
After achieving satisfactory airway anesthesia, most intubation techniques progress well to successful comple-tion. Blind techniques, retraction blades, or fiberscopes are commonly employed.
Friable tumors, abscesses, and impending obstructive airway tumors often require awake tracheostomy.