B.3. What features of the difficult airway can be noted on physical examination?
Answer:
Many anatomic abnormalities can be noted simply by performing a thorough airway exam. Visual inspection of the size of the mouth can alert the anesthesiologist to a constricted oral opening that can be seen in conditions such as scleroderma, epidermolysis bullosa, or congenital microstomia, which could prevent insertion of a laryngoscope. Micrognathia or maxillary protrusion often accompanies an anterior larynx, making glottic visualization during direct laryngoscopy impossible. This is seen in children with craniofacial syndromes, such as Pierre Robin sequence, Treacher Collins syndrome, Apert syndrome, or Crouzon syndrome. Macroglossia as a consequence of certain metabolic storage diseases (ie, Hurler syndrome, Hunter syndrome), cystic abnormalities, and hamartomatous tumors of the tongue (Goltz syndrome) can also make effective laryngoscopy impossible. Assessing the temporomandibular joint can reveal signs of ankylosis, which can occur in patients with juvenile rheumatoid arthritis and other autoimmune processes that can prevent adequate mouth opening. A narrow, high-arched palate can also suggest difficult tracheal intubation. One should evaluate a range of motion of the neck to reveal decreased neck extension, which can accompany some neuromuscular disorders, arthritic conditions, trauma, Klippel-Feil syndrome, or Goldenhar syndrome. Lastly, one should attempt to palpate the neck to assess for tracheal deviation. A preoperative chest radiograph might better serve to note tracheal deviation, as well as provide a baseline for the state of the lungs.
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