Effect of a Novel Anatomically Shaped Endotracheal Tube on Intubation-Related Injury<alt-title>Endotracheal Tube and Intubation-Related Injury</alt-title>

Abstract

Objectives To develop an anatomically shaped endotracheal tube (ETT) and to compare the degree of induced laryngeal injury of this ETT with that of a standard ETT using an animal model. Design Randomized controlled animal study. Subjects Eight Sus scrofa piglets (15-20 kg) randomly intubated with either a standard or a modified uncuffed ETT. Interventions The modified ETT was handcrafted by gluing and then trimming dry polyvinyl acetate foam circumferentially to the distal end of a standard uncuffed ETT. After intubation, the foam quickly self-expanded as it absorbed the secretions of the laryngopharynx and adopted the shape of the intraluminal airway. This conforming shape also sealed the larynx to allow for positive pressure ventilation. Both groups were intubated for 4 hours under constant hypoxic conditions (mean oxygen saturation Main Outcome Measures The severity of laryngeal injury graded on a scale from 0 to 4 (0 indicates normal; 1, epithelial compression; 2, epithelial loss; 3, subepithelial and glandular necrosis; and 4, perichondrium involvement). Results All of the specimens histologically demonstrated areas of inflammation and epithelial loss. The standard ETT caused substantial deep damage, with a mean (SD) severity score of 2.79 (0.74). The modified ETT caused mainly superficial damage, with a mean (SD) severity score of 1.65 (0.56) ( P Conclusion The modified ETT objectively caused less laryngotracheal damage compared with the standard ETT and may be of potential clinical benefit.