Procalcitonin kinetics in the prognosis of severe community-acquired pneumonia

Objectives: Procalcitonin (PCT) kinetics is a good prognosis marker in infectious diseases, but few studies of community-acquired pneumonia (CAP) have been performed in intensive care units (ICU). We analyzed the relationship between PCT kinetics and outcome in ICU patients with severe CAP. Design and setting: Prospective observational study in a 16-bed university hospital ICU. Patients: 100 critically ill patients with community-acquired pneumonia. Measurements and results: Median PCT was 5.2 ng/ml on day 1 and 2.9 ng/ml on day 3. It increased from day 1 to day 3 in nonsurvivors but decreased in survivors. In multivariate analysis four variables were associated with death: invasive ventilation (odds ratio 10-), multilobar involvement (5.6-), LOD score (6.9-), and PCT increase from day 1 to day 3 (4.5-). In intubated patients with a PCT level below 0.95 ng/ml on day 3 the survival rate was 95%. Conclusion: Increased PCT from day 1 to day 3 in severe CAP is a poor prognosis factor. A PCT level less than 0.95 ng/ml on day 3 in intubated patients is associated with a favorable outcome.