Differentiation of cardiac and pulmonary causes of acute shortness of breath

A method for differentiating in a human subject suffering from acute shortness of breath (dyspnea) between (i) a pulmonary disease, (ii) a cardiovascular complication, (iii) a cardiovascular complication accompanied by a pulmonary disease, and (iv) acute dyspnea without cardiovascular or pulmonary causes comprising the steps of

• determining an amount of pulmonary surfactant protein B (SP-B) in a sample from said subject,
• determining an amount of N-terminal pro-brain natriuretic peptide (NT-proBNP) in a sample from said subject, and
• comparing the amounts of SP-B and NT-proBNP determined with reference amounts of SP-B and NT-proBNP determined in a sample from a reference subject, wherein (i) a reference amount less than 125 pg/ml for NT-proBNP and a reference amount larger than 20,000 ng/ml for SP-B indicate diagnosis for pulmonary disease, (ii) a reference amount larger than 125 pg/ml but less than 3,200 pg/ml for NT-proBNP and a reference amount larger than 20,000 ng/ml for SP-B indicate diagnosis for cardiovascular complication, (iii) a reference amount larger than 3,200 pg/ml for NT-proBNP and a reference amount larger than 20,000 ng/ml for SP-B indicate diagnosis for pulmonary disease accompanied by a cardiovascular complication, and (iv) a reference amount less than 125 pg/ml for NT-proBNP and a reference amount less than 20,000 ng/ml for SP-B indicate diagnosis for acute dyspnea without cardiovascular or pulmonary causes.