title: Assessment of aspiration risk from dynamic modulation of endotracheal tube cuff pressure.
abstract: OBJECTIVE
  To assess the risk of aspiration using a novel valve circuit that dynamically modulates endotracheal tube cuff pressure during the ventilatory cycle using bench and live animal models.
  
  
  METHODS
  Animal model.
  
  
  METHODS
  The bench model consisted of a cuffed endotracheal tube inserted into an artificial trachea. Leakage of liquid around the cuff was measured after 4 hours of constant or dynamic modulation of cuff pressure at variable peak end expiratory pressures. In the porcine model, eight animals were ventilated with the modulating valve circuit and compared to eight controls ventilated with a constant cuff pressure (25 cm of water). Aspiration was monitored quantitatively using a pH probe (measured as voltage) and visually using fluoroscopy.
  
  
  RESULTS
  There was no difference in the amount of fluid leakage around the endotracheal tube cuff in the constant or dynamically modulated pressure-cuff groups in the bench or animal models.
  
  
  CONCLUSIONS
  Dynamically modulating endotracheal tube-cuff pressures to minimize tracheal mucosal damage does not increase the tendency to leak around the cuff compared to endotracheal tube cuffs inflated to a constant pressure.
  
  
  METHODS
  N/A.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, University of Toronto, The Hospital for Sick Children, Toronto, Canada.
authors.forename: Sohit P
authors.initials: SP
authors.lastname: Kanotra
authors.forename: Evan J
authors.initials: EJ
authors.lastname: Propst
authors.forename: Igor
authors.initials: I
authors.lastname: Luginbuehl
authors.forename: Paolo
authors.initials: P
authors.lastname: Campisi
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Fisher
authors.forename: Vito
authors.initials: V
authors.lastname: Forte
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D005471:Fluoroscopy; D007442:Intubation, Intratracheal / Q000009:adverse effects* / Q000295:instrumentation*; D008953:Models, Anatomic; D011175:Positive-Pressure Respiration / Q000295:instrumentation* / Q000379:methods; D011312:Pressure; D011897:Random Allocation; D012016:Reference Values; D063466:Respiratory Aspiration of Gastric Contents / Q000517:prevention & control*; D018570:Risk Assessment; D018709:Statistics, Nonparametric; D034421:Sus scrofa; D013552:Swine; D014132:Trachea / Q000293:injuries*
keywords: Mechanical ventilation; PEEP; airway; animal model; aspiration; bench top model; endotracheal tube; injury; intubation; larynx; modulation of cuff pressure