title: Polyurethane does not protect better than polyvinyl cuffed tracheal tubes from microaspirations.
abstract: BACKGROUND
  Mechanically ventilated patients are prone to develop ventilator associated pneumonia due to microaspirations of subglottic secretions around the endotracheal tube cuff (usually constructed of polyvinyl material). A novel polyurethane cuff has been designed to minimize these leakages. The aim of the study was to compare the tracheal sealing capacities between the two tubes.
  
  
  METHODS
  Twenty-nine consecutive patients from whom tracheal intubation was necessary as part of their care were randomized to receive either a polyvinyl HI-LO Evac® or a polyurethane SEALGUARD Evac® endotracheal tube. Patients requiring emergency intubation, with unstable hemodynamics or history of tracheal/laryngeal disease were excluded. For the entire study, cuff pressure was set at 30 cmH2O, and ventilator parameters were adjusted for a plateau pressure ≤30 cmH2O; Patients were fasting, placed in a strict 45° position during 12 hours and sedated if needed. After injection of 74 MBq 99mTc-DTPA diluted in 5 mL 0.9% NaCl just above the cuff, tracheal radioactivity was assessed sequentially (hourly from T0 to T6, then T8 and T12 hours) using a scintillation camera.
  
  
  RESULTS
  Sixteen polyurethane and 13 polyvinyl tubes were compared. Leakages were observed in 11/29 patients (38%) (5/16 polyurethane and 6/13 polyvinyl tubes [P=NS]). Leakages occurred more often in female (7/8) than in male patients (4/21) (P<0.001). Microaspirations were decreased with larger tubes (size 9 vs. ≤8.5: 24% vs. 75%; P=0.01), whatever the cuff membrane.
  
  
  CONCLUSIONS
  These preliminary results suggest that both tubes are poorly effective in preventing microaspirations.
authors.affiliation: Intensive Care Unit, CHU Mont-Godinne, Université Catholique de Louvain, 5530 Yvoir, Belgium. pierre.bulpa@uclouvain.be
authors.forename: P
authors.initials: P
authors.lastname: Bulpa
authors.forename: P
authors.initials: P
authors.lastname: Evrard
authors.forename: S
authors.initials: S
authors.lastname: Bouhon
authors.forename: F
authors.initials: F
authors.lastname: Schryvers
authors.forename: J
authors.initials: J
authors.lastname: Jamart
authors.forename: I
authors.initials: I
authors.lastname: Michaux
authors.forename: A
authors.initials: A
authors.lastname: Dive
authors.forename: T
authors.initials: T
authors.lastname: Vander Borght
authors.forename: B
authors.initials: B
authors.lastname: Krug
mesh_terms: D000328:Adult; D000368:Aged; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007442:Intubation, Intratracheal / Q000295:instrumentation* / Q000379:methods; D008297:Male; D008420:Manufactured Materials; D008875:Middle Aged; D011015:Pneumonia, Aspiration / Q000517:prevention & control*; D011140:Polyurethanes; D011145:Polyvinyls; D011446:Prospective Studies; D011877:Radionuclide Imaging; D014132:Trachea / Q000000981:diagnostic imaging
chemical_list: D011140:Polyurethanes; D011145:Polyvinyls