Comprehensive Preoperative Airway Grading

The purpose of this study is to evaluate a comprehensive preoperative airway examination using a 75-degree rigid laryngoscope. (It is important to note that this laryngoscope is routinely used in the speech pathology clinic where patients are not required to provide a written consent because of the limited and non-invasive nature of the examination) The investigators plan to accomplish this by grading a person's airway using a laryngoscopy view and obtain pictures to describe a person's supraglottic airway. The investigators will use these measures to assist the anesthesiologists of the day of surgery with the approach of securing the airway (traditional laryngoscopy versus video-assisted laryngoscopy versus fiberoptic-guided laryngoscopy).

The traditional test and parameters for the assessment of the airway are: The Mallampatti test, the Wilson airway assessment, evaluation of the atlantooccipital joint extension (neck mobility), the thyro-mental distance, the sterno-mental distance, mandibulo-hyoid distance, inter-incisor distance (mouth opening). Other investigators have proposed the use of radiographic assessment methods. These traditional tests are limited by the inability to visualize the posterior pharynx, tongue base, and glottis. Difficulty in intubation can be classified according to the view obtained during direct laryngoscopy into 4 grades. These four grades of laryngoscopic views were defined by Cormack and Lehane. At the present time, no single airway test can provide a high index of sensitivity and specificity for the prediction of a difficult airway. Therefore, it is common practice to use a combination of multiple tests and accept that there is still ambiguity when predicting airway challenges and the best approach to securing an airway.