title: Elevated plasma surfactant protein-B predicts development of acute respiratory distress syndrome in patients with acute respiratory failure.
abstract: Surfactant protein-B is a lung specific protein secreted into the air spaces by pulmonary epithelial type II cells that leaks into the bloodstream in increased amounts in patients with ARDS. To test whether elevated plasma levels of surfactant protein-B would predict the development of ARDS in patients with acute hypoxemic respiratory failure, plasma and lung injury scores were collected at study entry and daily thereafter for 3 d from 54 patients admitted to our intensive care unit. ARDS was defined as a new bilateral infiltrate on chest radiograph and a lung injury score > or = 2.5. Twenty patients developed ARDS, of whom seven died. Although the initial lung injury score was not predictive of ARDS, the initial plasma surfactant protein-B was predictive (area under the curve = 0.77 [0.63 to 0.90], nonparametric receiver-operating characteristic analysis). In this cohort, plasma surfactant protein-B was particularly predictive of ARDS when applied to patients suffering a direct lung insult (area under the curve = 0.87 [0.72 to 1.02]), with a sensitivity of 85% (95% CI: 55 to 98%) and specificity of 78% (40 to 97%) at a cutoff of 4,994 ng/ml.
authors.affiliation: Department of Critical Care Medicine, Flinders Medical Centre and School of Medicine, Flinders University, South Australia. bersten@flinders.edu.au
authors.forename: A D
authors.initials: AD
authors.lastname: Bersten
authors.forename: T
authors.initials: T
authors.lastname: Hunt
authors.forename: T E
authors.initials: TE
authors.lastname: Nicholas
authors.forename: I R
authors.initials: IR
authors.lastname: Doyle
mesh_terms: D000208:Acute Disease; D000368:Aged; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D000860:Hypoxia / Q000097:blood* / Q000150:complications*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011510:Proteolipids / Q000097:blood*; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants / Q000097:blood*; D011859:Radiography; D012128:Respiratory Distress Syndrome / Q000145:classification / Q000000981:diagnostic imaging / Q000209:etiology* / Q000401:mortality; D012131:Respiratory Insufficiency / Q000097:blood* / Q000150:complications*; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric
chemical_list: D015415:Biomarkers; D011510:Proteolipids; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants