title: Effect of a novel anatomically shaped endotracheal tube on intubation-related injury.
abstract: OBJECTIVE
  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.
  
  
  METHODS
  Randomized controlled animal study.
  
  
  METHODS
  Eight Sus scrofa piglets (15-20 kg) randomly intubated with either a standard or a modified uncuffed ETT.
  
  
  METHODS
  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 <70%) to enhance and accelerate intubation damage. They were then humanely killed, and the larynx and trachea were harvested for histologic examination.
  
  
  METHODS
  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 < .001).
  
  
  CONCLUSIONS
  The modified ETT objectively caused less laryngotracheal damage compared with the standard ETT and may be of potential clinical benefit.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, The Hospital for Sick Children, 555 University Ave, Toronto, ON M5G 1X8, Canada. a_gordin@rambam.health.gov.il
authors.forename: Arie
authors.initials: A
authors.lastname: Gordin
authors.forename: Neil K
authors.initials: NK
authors.lastname: Chadha
authors.forename: Paolo
authors.initials: P
authors.lastname: Campisi
authors.forename: Igor
authors.initials: I
authors.lastname: Luginbuehl
authors.forename: Glenn
authors.initials: G
authors.lastname: Taylor
authors.forename: Vito
authors.initials: V
authors.lastname: Forte
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D004867:Equipment Design; D007049:Iatrogenic Disease / Q000517:prevention & control; D007442:Intubation, Intratracheal / Q000009:adverse effects* / Q000295:instrumentation*; D007830:Larynx / Q000293:injuries*; D023421:Models, Animal; D011897:Random Allocation; D013552:Swine