title: Endotracheal tube intraluminal volume loss among mechanically ventilated patients.
abstract: OBJECTIVE
  To measure endotracheal tube intraluminal volume loss among mechanically ventilated patients.
  
  
  METHODS
  Prospective observational study.
  
  
  METHODS
  Medical intensive care unit (19 beds) of an urban university-affiliated teaching hospital.
  
  
  METHODS
  A total of 101 patients with acute respiratory failure requiring >24 hrs of mechanical ventilation.
  
  
  METHODS
  None.
  
  
  RESULTS
  Acoustic reflectometry was employed to measure the intraluminal volume of 13-cm endotracheal tube segments. The endotracheal tube segment volumes were statistically smaller among endotracheal tubes used in patients compared with unused endotracheal tubes (5.4 +/- 0.7 vs. 6.0 +/- 0.6 mL, p <.001). The average percentage difference in endotracheal tube segment volumes, between the unused endotracheal tubes and the endotracheal tubes used in patients, was 9.8% (range, 0-45.5%). The percentage difference in the endotracheal tube segment volumes increased significantly with increasing duration of tracheal intubation (r2 =.766, p <.001). The minimum diameter of the endotracheal tube segments was also statistically smaller among endotracheal tubes used in patients compared with the unused endotracheal tubes (7.5 +/- 0.4 vs. 6.7 +/- 1.2 mm, p <.001).
  
  
  CONCLUSIONS
  Endotracheal tube intraluminal volume loss is common among patients with acute respiratory failure requiring mechanical ventilation and increases with prolonged tracheal intubation.
authors.affiliation: Pulmonary and Critical Care Division, Washington University School of Medicine, St. Louis, MO 63110, USA.
authors.forename: Chirag
authors.initials: C
authors.lastname: Shah
authors.forename: Marin H
authors.initials: MH
authors.lastname: Kollef
mesh_terms: D018441:Biofilms; D015331:Cohort Studies; D016638:Critical Illness / Q000628:therapy; D020878:Device Removal; D004868:Equipment Failure; D004869:Equipment Safety; D005260:Female; D005500:Follow-Up Studies; D006784:Hospitals, Teaching; D006801:Humans; D007362:Intensive Care Units; D007442:Intubation, Intratracheal / Q000295:instrumentation* / Q000379:methods; D008297:Male; D011336:Probability; D011446:Prospective Studies; D012121:Respiration, Artificial / Q000295:instrumentation* / Q000379:methods; D012128:Respiratory Distress Syndrome / Q000175:diagnosis / Q000628:therapy*; D018570:Risk Assessment; D016896:Treatment Outcome; D012122:Ventilators, Mechanical / Q000009:adverse effects*