Although VAP is the most frequent cause of death in hospital for patients with respiratory failure [39,40], the diagnosis of VAP is difficult. The optimal invasive procedure for diagnosing selleck chemicals Baricitinib HAP or VAP remains poorly defined [9,10]. Indeed, one study demonstrated that 29% of clinically suspected VAP cases were disproved by autopsy results [41]. In this study, microbiological proof of infection was possible in about 67% of the patients. This is in good agreement with findings in large sepsis trials where microbiological proof was possible in 41 to 51% of the patients with airway infections [42,43].It should be noted that the immunoluminometric assay for PCT measurement applied in this study has been replaced today by more modern techniques with a higher accuracy especially in the low range of PCT levels.

Such accuracy is a prerequisite when using PCT for antibiotic stewardship [20]. This study was focused on high PCT concentrations for their association with mortality and organ dysfunction. It is unlikely that such a relationship is affected by the type of assay.Measurement of PCT levels in addition to the clinical judgement may offer a solution for this diagnostic dilemma since our data suggest that baseline PCT levels greater than 1.1 ng/ml identify a group of ICU patients with a high risk to develop multiorgan dysfunction followed by death. The quality of mortality prediction was similar to the APACHE II score. These data confirm the observation by Luyt et al., who found a PCT threshold of 1 ng/ml to predict unfavorable outcome [19].

Furthermore, non-survivors showed no decrease in PCT suggesting that pneumonia remained uncontrolled. Assessing adequacy of antimicrobial therapy was not part of the study hypothesis and would have been beyond the scope of this trial. However, PCT measurement offers the possibility of being a marker for monitoring therapeutic success or failure, since successful therapy is associated with a decrease in PCT levels. A PCT guided algorithm has been shown to reduce duration of antibiotic therapy without affecting patients’ safety [22,44].ConclusionsIn patients with severe pneumonia (CAP, VAP, HAP), PCT is associated with the severity of illness and is a good prognostic marker of morbidity and mortality in patients with pneumonia in demand of mechanical ventilation.

The severity of illness as reflected by the degree of organ dysfunction may be a more important determinant of PCT levels than the type or cause of pneumonia.Key messages? Procalcitonin (PCT) concentrations are associated with the severity of illness in patients with severe pneumonia in demand of mechanical ventilation.? PCT is a good prognostic marker of morbidity and mortality in these patients.? The severity of illness as reflected by the degree of organ dysfunction may be a more important determinant GSK-3 of PCT levels than the type or cause of pneumonia.