title: Determining the aetiology of pulmonary oedema by the oedema fluid-to-plasma protein ratio.
abstract: We hypothesised that the oedema fluid-to-plasma protein (EF/PL) ratio, a noninvasive measure of alveolar capillary membrane permeability, can accurately determine the aetiology of acute pulmonary oedema. 390 mechanically ventilated patients with acute pulmonary oedema were enrolled. A clinical diagnosis of acute lung injury (ALI), cardiogenic pulmonary oedema or a mixed aetiology was based on expert medical record review at the end of hospitalisation. The EF/PL ratio was measured from pulmonary oedema fluid and plasma samples collected at intubation. 209 patients had a clinical diagnosis of ALI, 147 had a diagnosis of cardiogenic pulmonary oedema and 34 had a mixed aetiology. The EF/PL ratio had an area under the receiver-operating curve of 0.84 for differentiating ALI from cardiogenic pulmonary oedema. Using a predefined cut-off of 0.65, the EF/PL ratio had a sensitivity of 81% and a specificity of 81% for the diagnosis of ALI. An EF/PL ratio >/=0.65 was also associated with significantly higher mortality and fewer ventilator-free days. Noninvasive measurement of the EF/PL ratio is a safe and reliable bedside method for rapidly determining the aetiology of acute pulmonary oedema that can be used at the bedside in both developed and developing countries.
authors.affiliation: Division of Allergy, Pulmonary and Critical Care Medicine, Dept of Medicine, Vanderbilt University School of Medicine, T1218 MCN, 1161 21st Avenue S, Nashville, TN 37232-2650, USA. lorraine.ware@vanderbilt.edu
authors.forename: L B
authors.initials: LB
authors.lastname: Ware
authors.forename: R D
authors.initials: RD
authors.lastname: Fremont
authors.forename: J A
authors.initials: JA
authors.lastname: Bastarache
authors.forename: C S
authors.initials: CS
authors.lastname: Calfee
authors.forename: M A
authors.initials: MA
authors.lastname: Matthay
mesh_terms: D000328:Adult; D000368:Aged; D001798:Blood Proteins / Q000032:analysis*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000378:metabolism; D010539:Permeability; D011650:Pulmonary Alveoli / Q000378:metabolism; D011654:Pulmonary Edema / Q000097:blood / Q000175:diagnosis* / Q000209:etiology*; D012372:ROC Curve; D012128:Respiratory Distress Syndrome / Q000097:blood / Q000175:diagnosis* / Q000209:etiology*
chemical_list: D001798:Blood Proteins; D010100:Oxygen