PROPOSED GRADING SYSTEM FOR SUBGLOTTIC STENOSIS BASED ON ENDOTRACHEAL-TUBE SIZES

The classification of airway stenoses has been a problem for many year s. As a result, both intradepartmental and interdepartmental compariso ns of airway sizes remain difficult. It follows that comparisons of th erapeutic maneuvers are even more difficult. A system is proposed that is simple, reproducible, and based on a readily available reference s tandard. Endotracheal tubes, which are manufactured to high standards of precision and accuracy, can be used to determine the size of an obs tructed airway at its smallest point. The endotracheal tube that will pass through the lumen, if one exists, and tolerate normal leak pressu res (10 to 25 cm H2O), can be compared to the expected age-appropriate endotracheal tube size. By using the outside diameters of the endotra cheal tubes, the maximum percentage of airway obstruction can be deter mined. We present a conversion of tube size to the proposed grading sc ale: grade I up to 50% obstruction, grade II from 51% to 70%, and grad e III above 70% with any detectable lumen. An airway with no lumen is assigned to grade IV.