It is worth noting that the areas under the receiver operating characteristic curve achieved by both markers were comparable sellekchem (mean (standard deviation)) 0.697 (0.051) and 0.713 (0.048), respectively; P = not significant) (Figure (Figure2).2). In addition, we found that the combination of the two led to a significant, although slight, improvement in the predictive value of each factor taken alone (mean (standard deviation)) area under the receiver operating characteristic curve = 0.758 (0.048) (Figure (Figure33).Figure 2Procalcitonin variation and Sepsis-related Organ Failure Assessment for differentiating between survivors and nonsurvivors. Receiver operating characteristic curves of procalcitonin variation between day 2 and day 3 after the onset of sepsis (red line) …

Figure 3Procalcitonin variation in combination with Sepsis-related Organ Failure Assessment for differentiating between survivors and nonsurvivors. Receiver operating characteristic curves of procalcitonin variation between day 2 and day 3 after the onset of …DiscussionWe show herein that the PCT kinetic within the first 48 hours of management of sepsis could be significantly different according to the appropriateness of the first-line empirical antibiotic therapy. Actually, PCT variations between D2 and D3 were shown to be critical since a significantly greater PCT decline within this period was expected in the patients with appropriate empirical antibiotic therapy. In addition, a trend toward a greater rise in PCT between D1 and D2 was observed in patients with inappropriate antibiotics as compared with those with appropriate therapy.

As a result, our findings suggest that patient management might be reassessed if PCT does not decrease by 30% between D2 and D3. In such cases, empirical antibiotic therapy modification towards a broader spectrum should be considered while the microbiological findings, if any, are still pending.Since the adequacy of early management of critically ill patients with sepsis including antibiotic administration is thought to be critical, objective markers are required. Given the lack of reliability of clinical endpoints such as body temperature, biomarkers are of potential interest. Among them, PCT has appeared as one of the most promising in the setting of severe bacterial sepsis [22].

Only a few studies about the early time-dependent changes of PCT have so far been published, and none of them focused on the appropriateness of the first-line antibiotic therapy. Some experimental data do, however, support the fact that PCT elevation is related to the bacterial load [23]. PCT kinetics during the first days of sepsis could therefore Entinostat reflect the efficacy of the host immune response with respect to bacterial clearance, with or without the contribution of an appropriate antibiotic therapy.