(1055) ETT Size Selection: A Case Review of Overdistension and Tracheal Tear

Introduction: A growing body of literature suggests that endotracheal tube (ETT) size should be based on gender and height. Large-for-airway size endotracheal tubes may be associated with airway injury, such as glottic or tracheal injury. However, no specific guidelines for ET size selection currently exist. We review the factors leading to a tracheal tear following emergent intubation, which highlights ETT size selection and the process of inflating the endotracheal cuff.

Description: A 5'1" 62-year-old female was transferred to the medical intensive care unit for hypoxic respiratory failure due to aspiration of gastric contents. She required emergent intubation due to progressive hypoxia. A 7.5 cuffed ETT was placed 24cm at the lip, and the operator inflated the cuff following usual practice with a 10 cc syringe (same syringe used to check cuff integrity). A post-intubation chest radiograph revealed an image concerning for cuff-related tracheal overdistension (measuring 32 mm) and right main stem intubation. A review of prior imaging revealed a tracheal diameter of 12 mm. These findings led to a concern for airway injury, for which a bronchoscopy was performed; this demonstrated a full-thickness tracheal tear 2 cm proximal to the carina. A multidisciplinary and interprofessional review of the process for intubation highlighted 2 potential causes for the event: 1) ETT size too large for the patient based on gender and height and 2) the filling the ETT cuff with a 10 cc syringe. Our process for ETT tube selection and balloon inflation was changed. We now have a ETT guide, and use a 5 cc syringe inflated to minimal occlusion volume, followed by cuff pressure assessment.

Discussion: Airway injuries, including tracheal tears are known complications of orotracheal intubation. Patient height and gender correlate to laryngeal and tracheal length and diameter. The risk for vocal cord, laryngeal, and tracheal injury increases as the size of the ETT discrepancy increases. We developed guidance for ETT size guide based on gender and height based on literature. Further prospective studies are needed to define appropriate ETT size selection and risk of injury related to ETT size selection.