title: Intermittent subglottic secretion drainage may cause tracheal damage in patients with few oropharyngeal secretions.
abstract: OBJECTIVE
  Injurious prolapse of tracheal mucosa into the suction port has been reported in up to 50% of intubated patients receiving continuous aspiration of subglottic secretions. We investigated whether similar injury could be inflicted by automated intermittent aspiration.
  
  
  METHODS
  Six consecutive patients, intubated with the Mallinckrodt TaperGuard Evac™ endotracheal tube, were studied. A flow sensor was placed between the vacuum regulating system and the mucus collector. Intermittent suctioning was performed at a pressure of -125 mmHg with a 25s interval and duration of 15s. After 24h, a CT scan of the tracheal region was performed.
  
  
  RESULTS
  Excessive negative suction pressure, a fast drop in aspiration flow to zero, and important "swinging" movements of secretions in the evacuation line were observed in all patients. Oral instillation of antiseptic mouthwash restored normal aspiration flow and secretion mobility. CT imaging showed marked entrapment of tracheal mucosa into the suction port in all patients.
  
  
  CONCLUSIONS
  In patients with few oropharyngeal secretions, automated intermittent subglottic aspiration may result in significant and potential harmful invagination of tracheal mucosa into the suction lumen. A critical amount of fluid must be present in the oropharynx to assure adequate and safe aspiration.
authors.affiliation: Intensive Care Department, University Hospital, Vrije Universiteit Brussel, Laarbeeklaan, 101, B-1090 Brussels, Belgium(1). Electronic address: emiel.suys@uzbrussel.be.
authors.forename: E
authors.initials: E
authors.lastname: Suys
authors.forename: K
authors.initials: K
authors.lastname: Nieboer
authors.forename: W
authors.initials: W
authors.lastname: Stiers
authors.forename: J
authors.initials: J
authors.lastname: De Regt
authors.forename: L
authors.initials: L
authors.lastname: Huyghens
authors.forename: H
authors.initials: H
authors.lastname: Spapen
mesh_terms: D000368:Aged; D006801:Humans; D007442:Intubation, Intratracheal; D008297:Male; D008875:Middle Aged; D009960:Oropharynx / Q000502:physiology*; D010865:Pilot Projects; D011446:Prospective Studies; D013396:Suction / Q000009:adverse effects* / Q000379:methods*; D014132:Trachea / Q000293:injuries*
keywords: Aspiration; Endotracheal tube; Mucosal damage; Subglottic secretion drainage