Predictive value of procalcitonin decrease in patients with severe sepsis: a prospective observational study

Introduction: This prospective study investigated the predictive value of procalcitonin (PCT) for survival in 242 adult patients with severe sepsis and septic shock treated in intensive care. Methods: PCT was analyzed from blood samples of all patients at baseline, and 155 patients 72 hours later. Results: The median PCT serum concentration on day 0 was 5.0 ng/ml (interquartile range (IQR) 1.0 and 20.1 ng/ml) and 1.3 ng/ml (IQR 0.5 and 5.8 ng/ml) 72 hours later. Hospital mortality was 25.6% (62/242). Median PCT concentrations in patients with community-acquired infections were higher than with nosocomial infections (P = 0.001). Blood cultures were positive in 28.5% of patients (n = 69), and severe sepsis with positive blood cultures was associated with higher PCT levels than with negative cultures (P = < 0.001). Patients with septic shock had higher PCT concentrations than patients without (P = 0.02). PCT concentrations did not differ between hospital survivors and nonsurvivors (P = 0.64 and P = 0.99, respectively), but mortality was lower in patients whose PCT concentration decreased > 50% (by 72 hours) compared to those with a < 50% decrease (12.2% vs. 29.8%, P = 0.007). Conclusions: PCT concentrations were higher in more severe forms of severe sepsis, but a substantial concentration decrease was more important for survival than absolute values.