[Is procalcitonin measurement useful in managing respiratory tract infections?]

Better use of current antibiotics is warranted to curb increasing antimicrobial resistance rates. Procalcitonin guidance can safely reduce antibiotic usage when used to initiate or discontinue antibiotics in adult patients with a respiratory tract infection. However, the claimed reductions in antibiotic usage are mainly achieved in patients with acute bronchitis and exacerbations of COPD, conditions for which guidelines already discourage antibiotic treatment. Sequential procalcitonin measurements can also reduce the treatment duration of community-acquired pneumonia from 10-12 to 5-7 days, which is, however, already the recommended treatment duration for in- and outpatients under the current Dutch guidelines. Investigating why physicians do not follow these guidelines might therefore be more helpful than introducing new laboratory tests such as that for procalcitonin. Determination of the aetiology of community-acquired pneumonia is an important clinical problem. Host gene expression pattern assays are promising for diagnosis of the aetiology of acute respiratory illness. This might be helpful to guide antibiotic therapy.