title: Effect of airway pressure display on interobserver agreement in the assessment of vascular pressures in patients with acute lung injury and acute respiratory distress syndrome.
abstract: BACKGROUND
  Previous investigations have identified significant interobserver variability in the measurements of central venous pressure and pulmonary artery occlusion pressure in critically ill patients. Large interobserver variability in the measurement of vascular pressures could potentially lead to inappropriate treatment decisions.
  
  
  OBJECTIVE
  We postulated that adding an airway pressure signal (Paw) to pressure tracings of central venous pressure and pulmonary artery occlusion pressure would improve interobserver agreement by facilitating identification of end-expiration.
  
  
  METHODS
  To test this hypothesis, six independent experts used a standard protocol to interpret strip-chart recordings of central venous pressure and pulmonary artery occlusion pressure with or without Paw. Two observers were said to agree if their measurements were within 2 mm Hg of each other. SETTING/SUBJECTS/INTERVENTIONS: A total of 459 strip-chart recordings (303 without Paw and 156 with Paw) were obtained from 121 patients enrolled in the ARDSnet Fluids and Catheters Treatment Trial (FACTT) in 16 different hospitals.
  
  
  RESULTS
  Agreement within 2 mm Hg between two measurements was 79% for central venous pressure strips without Paw vs. 86% with Paw. For pulmonary artery occlusion pressure, agreement increased from 71% without Paw to 83% with Paw. The increase in agreement with the addition of Paw was greater for strips demonstrating >8 mm Hg phasic respiratory variation compared with strips demonstrating less phasic respiratory variation.
  
  
  CONCLUSIONS
  Paw display is a simple, inexpensive method to facilitate the identification of end-expiration that can significantly improve interobserver agreement.
authors.affiliation: Division of Biological Sciences, University of Chicago Pritzker School of Medicine, Chicago, IL, USA.
authors.forename: K
authors.initials: K
authors.lastname: Rizvi
authors.forename: B P
authors.initials: BP
authors.lastname: Deboisblanc
authors.forename: J D
authors.initials: JD
authors.lastname: Truwit
authors.forename: G
authors.initials: G
authors.lastname: Dhillon
authors.forename: A
authors.initials: A
authors.lastname: Arroliga
authors.forename: B D
authors.initials: BD
authors.lastname: Fuchs
authors.forename: K K
authors.initials: KK
authors.lastname: Guntupalli
authors.forename: D
authors.initials: D
authors.lastname: Hite
authors.forename: D
authors.initials: D
authors.lastname: Hayden
mesh_terms: D000403:Airway Resistance / Q000502:physiology*; D001795:Blood Pressure Determination / Q000706:statistics & numerical data*; D002496:Central Venous Pressure / Q000502:physiology*; D003422:Critical Care / Q000379:methods*; D006801:Humans; D006874:Hydrostatic Pressure; D007318:Inservice Training; D055370:Lung Injury; D008991:Monitoring, Physiologic / Q000706:statistics & numerical data; D015588:Observer Variation; D011175:Positive-Pressure Respiration / Q000379:methods*; D011669:Pulmonary Wedge Pressure / Q000502:physiology*; D011785:Quality Assurance, Health Care; D015203:Reproducibility of Results; D012128:Respiratory Distress Syndrome / Q000503:physiopathology / Q000628:therapy*; D012815:Signal Processing, Computer-Assisted; D014159:Transducers