Markers of acute inflammation in assessing and managing lower respiratory tract infections: focus on procalcitonin  B. Müller, C. Prat  Clinical Microbiology and Infection  Volume 12, Pages 8-16 (January 2006) DOI: 10.1111/j.1469-0691.2006.01654.x Copyright © 2006 European Society of Clinical Infectious Diseases Terms and Conditions

Fig. 1 Rational use of procalcitonin in routine clinical practice. These cut-off ranges are dependent on the clinical context and have to be adapted accordingly. For example, lower cut-off ranges are appropriate in patients with markedly impaired pulmonary reserve, and higher cut-off ranges are appropriate in patients with systemic inflammatory response syndrome on an intensive care unit. The course of procalcitonin yields important additional information, and follow-up measurements can be helpful to improve diagnostic accuracy and to support treatment decisions. The use of rapid and sensitive assays is needed for antibiotic stewardship. (Adapted and updated from Christ-Crain M, Müller B. Procalcitonin in bacterial infections – hype, hope, more or less? SwissMedWkly 2005; 135: 451–60.) COLD, chronic obstructive lung disease; ICU, intensive care unit; PCT, procalcitonin; RTI, respiratory tract infection. Clinical Microbiology and Infection 2006 12, 8-16DOI: (10.1111/j.1469-0691.2006.01654.x) Copyright © 2006 European Society of Clinical Infectious Diseases Terms and Conditions

Fig. 2 Protocol for the classification, management and monitoring of patients according to the procalcitonin level and the associated probability of bacterial infection, as used in the ‘ProRESP’ and the ‘ProCAP’ study [25]. CAP, community-acquired pneumonia; COLD, chronic obstructive lung disease; CURB, confusion, urea nitrogen, respiratory rate, blood pressure; GOLD, Global Initiative for Chronic Obstructive Lung Disease; ICU, intensive care unit; PCT, procalcitonin; PSI, Pneumonia Severity Index; SaO2, arterial blood oxygen saturation. *Involving Staphylococcus aureus, Klebsiella pneumoniae, anaerobic organisms, empyema or abscesses. Clinical Microbiology and Infection 2006 12, 8-16DOI: (10.1111/j.1469-0691.2006.01654.x) Copyright © 2006 European Society of Clinical Infectious Diseases Terms and Conditions