Development of a model-based clinical sepsis biomarker for critically ill patients

作者：Lin Jessica^*; Parente Jacquelyn D; Chase J Geoffrey; Shaw Geoffrey M; Blakemore Amy J; LeCompte Aaron J; Pretty Christopher; Razak Normy N; Lee Dominic S; Hann Christopher E; Wang Sheng Hui

来源：Computer Methods and Programs in Biomedicine, 2011, 102(2): 149-155.

DOI：10.1016/j.cmpb.2010.04.002

• Sepsis
• Insulin sensitivity
• Biomarker
• Diagnosis
• Receiver operator characteristic
• Glucose control
• Real-time clinical application

Sepsis occurs frequently in the intensive care unit (ICU) and is a leading cause of admission, mortality, and cost. Treatment guidelines recommend early intervention, however positive blood culture results may take up to 48 h. Insulin sensitivity (SO is known to decrease with worsening condition and could thus be used to aid diagnosis. Some glycemic control protocols are able to accurately identify insulin sensitivity in real-time.
Hourly model-based insulin sensitivity S-1 values were calculated from glycemic control data of 36 patients with sepsis. The hourly S-1 is compared to the hourly sepsis score (ss) for these patients (ss = 0-4 for increasing severity). A multivariate clinical biomarker was also developed to maximize the discrimination between different ss groups. Receiver operator characteristic (ROC) curves for severe sepsis (ss >= 2) are created for both SI and the multivariate clinical biomarker.
Insulin sensitivity as a sepsis biomarker for diagnosis of severe sepsis achieves a 50% sensitivity, 76% specificity, 4.8% positive predictive value (PPV), and 98.3% negative predictive value (NPV) at an SI cut-off value of 0.00013 L/mU/min. Multivariate clinical biomarker combining Si, temperature, heart rate, respiratory rate, blood pressure, and their respective hourly rates of change achieves 73% sensitivity, 80% specificity, 8.4% PPV, and 99.2% NPV. Thus, the multivariate clinical biomarker provides an effective real-time negative predictive diagnostic for severe sepsis. Examination of both inter- and intra-patient statistical distribution of this biomarker and sepsis score shows potential avenues to improve the positive predictive value.

• 出版日期2011-5