Orocephalometry and airway control in obese sleep-disordered breathers, obese normals, and matched controls undergoing general anesthesia.

Airway patency in conscious, normal humans is maintained by a complex orchestration of airway dilator muscles and reflex pathways yet is easily perturbed. Using patients at high risk for airway obstruction during anesthesia, as well as matched controls, this study sought (1) to determine if selected observations would contribute to our understanding of upper airway obstruction, and (2) to scientifically ground our clinical airway management interventions. The "at risk" patients tended to differ significantly from the controls with respect to a number of anthropometric and subjective measures which sought to describe the obstructive phenomena. At risk subjects were characterized as having a much greater incidence of induction and emergence obstruction, an abbreviated mental-hyoid distance, a flattened, compressed anterior-posterior craniofacial architecture, retrognanthism, relative macroglossia, and a narrower, bulky oropharynx. A theoretical model of airway obstruction was proposed characterizing the pharynx as a "collapsible tube" especially vulnerable in conditions such as sleep disordered breathing.