Can serum procalcitonin levels help interpret indeterminate chest radiographs in patients hospitalized with acute respiratory illness?

Abstract

BACKGROUNDClinical diagnosis of pneumonia is difficult and chest radiographs often indeterminate, leading to incorrect diagnoses and antibiotic overuse.OBJECTIVETo determine if serum procalcitonin (ProCT) could assist in managing patients with respiratory illness and indeterminate radiographs.DESIGNSubjects were prospectively enrolled during 2 consecutive winters.SETTINGA 520‐bed hospital in Rochester, NY.PATIENTSFive hundred twenty‐eight adults admitted with acute respiratory illness were enrolled.MEASUREMENTSSerum ProCT, admission diagnoses, and chest radiographic findings were used to derive receiver operating characteristics curves to assess predictive accuracy of ProCT for the presence of infiltrates.RESULTSSubjects with pneumonia had higher ProCT (median 0.27 ng/ml) than those with exacerbations of chronic obstructive pulmonary disease (0.08 ng/ml), acute bronchitis (0.09 ng/ml), or asthma (0.06 ng/ml). ProCT had moderate accuracy for the presence of infiltrates (area under curve [AUC] 0.72), when indeterminate radiographs were independently classified as infiltrates by a pulmonologist evaluating patients.CONCLUSIONSProCT may be useful in diagnosing pneumonia when chest radiographs are indeterminate. Journal of Hospital Medicine 2013;8:61–67. © 2012 Society of Hospital Medicine