Marked Elevation in Serum Procalcitonin Levels Do Not Correlate With Severity of Disease or Mortality in Hospitalized Patients: A Retrospective Study

Abstract

Background: Bacteremia and sepsis are significant contributors to the morbidity, mortality, and economic burden of health care systems worldwide. Procalcitonin has been identified as a potentially useful marker of disease and severity in sepsis. However, the assumption that greater procalcitonin levels correlate with greater burden of disease has not been adequately studied. Methods: A retrospective chart review of adult patients admitted to an urban teaching hospital with suspected sepsis was undertaken to test the association of elevated procalcitonin (>30 ng/mL) with other markers of sepsis (lactic acid, white blood cell count, percent bands), severity of disease (Sequential Organ Failure Assessment [SOFA] and Acute Physiology and Chronic Health Evaluation–II [APACHE II] scores), and mortality. Results: In total, 168 patients were identified over 18 months (42% ward, 11% Stepdown, 44% medical intensive care unit [MICU], 2% surgical intensive care unit (STICU), 1% gynecology [GYN]). The Spearman correlation analysis showed that serum procalcitonin level did not correlate with SOFA ( P = .238) or APACHE II ( P = .918) scores on admission, and did not correlate with survival (Kruskal-Wallis test, P = .937). However, higher serum procalcitonin levels were associated with patients who had positive blood cultures (Kruskal-Wallis test, P = .0016 for Gram-positive and P = .0007 for Gram-negative bacteria). Lactic acid levels on admission strongly correlated with SOFA APACHE II (the Spearman correlation, P 30 ng/mL do not appear to correlate with the severity of disease in a sample of patients with markedly elevated initial procalcitonin levels.