1504. Use of a Combination Biomarker Algorithm to Identify Intensive Care Unit Patients with Suspected Sepsis at Very Low Likelihood of Bacterial Infection
Session: Poster Abstract Session: Antimicrobial Stewardship: Role of Diagnostics
Saturday, October 10, 2015
Room: Poster Hall
Posters
  • 1504_IDWeek.pdf (468.4 kB)
  • Background: Sepsis remains a diagnostic challenge in the intensive care unit (ICU), and the use of biomarkers may help in differentiating bacterial sepsis from other causes of systemic inflammatory syndrome (SIRS). The goal of this study was to assess test characteristics of a number of biomarkers for identifying ICU patients with a very low likelihood of bacterial sepsis.

    Methods: A prospective cohort study was conducted in a medical ICU of a university hospital. Patients with presumed bacterial sepsis were consecutively enrolled from January 2012 to May 2013. Concentrations of nine biomarkers (α-2 macroglobulin, C-reactive protein [CRP], ferritin, fibrinogen, haptoglobin, procalcitonin [PCT], serum amyloid A, serum amyloid P, and tissue plasminogen activator), were determined at baseline, 24 hours, 48 hours, and 72 hours after enrollment. Performance characteristics were calculated for varying combinations of biomarkers for discrimination of bacterial sepsis from other causes of SIRS.

    Results: Seventy patients were included during the study period; 31 (44%) had documented bacterial sepsis and 39 (56%) had other causes of SIRS. PCT and CRP values were significantly higher at all measured timepoints in patients with bacterial sepsis (Figure 1). The combination of PCT and CRP demonstrated high discriminatory ability (AUC of 0.810 for the 24 hour timepoint, Figure 2, receiver-operating characteristic [ROC] curves for a. PCT, b. CRP, c. combination of PCT and CRP, d. combination of PCT and CRP with interaction), and was superior to that of the individual biomarkers. A number of combinations of PCT and CRP, using varying cutoff values and measurement timepoints, demonstrated high negative predictive values (81.1%-85.7%) and specificities (63.2%-79.5%) for diagnosing bacterial sepsis.

    Conclusion: Combinations of PCT and CRP demonstrated high ability to discriminate bacterial sepsis from other causes of SIRS in medical ICU patients. These biomarkers may therefore be of significant utility for diagnosing bacterial sepsis in this population when interpreted in the context of other clinical and laboratory assessments. Future studies should focus on the use of these algorithms to improve antibiotic use in the ICU setting.

    Jennifer Han, MD, MSCE1, Irving Nachamkin, DrPH, MPH, FIDSA2, Susan Coffin, MD, MPH, FPIDS3, Jeffrey S. Gerber, MD, PhD3, Barry Fuchs, MD4, Charles Garrigan, MB2, Xiaoyan Han, MS5, Warren Bilker, PhD5, Jacqueleen Wise, BA5, Pam Tolomeo, MPH5, Ebbing Lautenbach, MD, MPH, MSCE, FIDSA, FSHEA1 and for the Centers for Disease Control and Prevention (CDC) Prevention Epicenters Program, (1)Division of Infectious Diseases, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, (2)Department of Pathology and Laboratory Medicine, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, (3)Department of Pediatrics, Division of Infectious Diseases, The Children's Hospital of Philadelphia, Philadelphia, PA, (4)Division of Pulmonary Medicine and Critical Care, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, (5)Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA

    Disclosures:

    J. Han, None

    I. Nachamkin, None

    S. Coffin, None

    J. S. Gerber, None

    B. Fuchs, None

    C. Garrigan, None

    X. Han, None

    W. Bilker, None

    J. Wise, None

    P. Tolomeo, None

    E. Lautenbach, None

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