Usefulness of procalcitonin clearance as a prognostic biomarker in septic shock. A prospective pilot study.

OBJECTIVE To evaluate procalcitonin clearance as a prognostic biomarker in septic shock. DESIGN Prospective, observational pilot study. SETTING Intensive care unit. PATIENTS Patients admitted to the ICU due to septic shock and multiorgan dysfunction. INTERVENTIONS Serum concentrations of procalcitonin were determined within 12h of onset of septic shock and multiorgan dysfunction (coinciding with admission to the ICU), and the following extractions were obtained after 24, 48 and 72h in patients who survived. DATA COLLECTED Demographic data, Acute Physiology and Chronic Health Evaluation II score, and Sequential Organ Failure Assessment score, data on the primary focus of infection, and patient outcome (ICU mortality). RESULTS Procalcitonin clearance was higher in survivors than in non-survivors, with significant differences at 24h (73.9 [56.4-83.8]% vs 22.7 [-331-58.4], p<0.05) and 48h (81.6 [71.6-91.3]% vs -7.29 [-108.2-82.3], p<0.05). The area under the ROC curve was 0.74 (95%CI, 0.54-0.95, p<0.05) for procalcitonin clearance at 24h, and 0.86 (95%CI, 0.69-1.0, p<0.05) at 48h. CONCLUSIONS ICU mortality was associated to sustained high procalcitonin levels, suggesting that procalcitonin clearance at 48h may be a valuable prognostic biomarker.