An assessment of the predictors of difficult intubation in patients with acromegaly.

Various clinical signs have been used for assessing difficult intubation in patients with acromegaly. These signs include the modified Mallampati classification, measurement of thyromental distance and head and neck movements. Some authors have also tried to establish a relationship between growth hormone levels and difficult intubation. We hypothesized that duration of symptoms in patients with acromegaly may have an association with difficult airway and difficult laryngoscopy. In this prospective study we evaluated tests of airway assessment such as: (i) the Mallampati grade; (ii) the thyromental distance; and (iii) the laryngoscopic grade (Cormack-Lehane). The growth hormone levels and the duration of disease symptoms were also examined. Significant correlation was observed between the Cormack-Lehane and Mallampati gradings (p = 0.05; rho = 19.3%), and between the thyromental distance and the duration of the symptoms (p = 0.03; rho = 26.9%). The incidence of Mallampati III and IV grades was higher in patients with acromegaly. Increased thyromental distance was noted in patients with a long duration of disease. However, increased thyromental distance was not associated with difficult laryngoscopy.