A-359 Performance of Measured TCO2 on the epoc Analyzer

Abstract

Abstract Background The epoc Blood Analysis System (Siemens, Tarrytown, NY) performs blood gases, electrolytes, and metabolites using a Blood Gas, Electrolyte and Metabolite (BGEM) Test Card on 92 uL of whole blood. The BGEM Test Card uses potentiometric sensors to measure sodium, potassium, chloride, ionized calcium, pH, pCO2; amperometric sensors to measure pO2, glucose, creatinine, and lactate; and a conductometric sensor to measure hematocrit. Results are available in 3–10 minutes, depending upon the time of sample injection. TJUH implemented epoc in its ICUs in 2012 to provide rapid, whole blood Point of Care (POC) results and has expanded to other locations (Emergency Department, Outpatient Radiology, Cardiothoracic Surgery). While previous epoc cards provided calculated TCO2 (cTCO2), Siemens recently added measured TCO2 (mTCO2; combination of potentiometric sensors and calculation) to its BGEM card. We evaluated this card for future use. Methods Precision and method comparison studies were performed at our Center City location. Inter- and intra-precision studies were performed on two levels of controls (Eurotrol, Elizabethtown, KY). Whole blood was collected in heparinized syringes from 20 patients. Comparison studies were performed on the ABL800 (Radiometer, Brea, CA). We simultaneously compared epoc mTCO2 against epoc cTCO2 and against the cTCO2 on the ABL800. Results Intra-assay precision for epoc mTCO2 (n = 20, 2 devices) was 0.8%CV and 2.3%CV for Levels 1 and 3, respectively. Inter-assay precision for epoc mTCO2 (n = 20, 2 devices over 10 days) was 1.1%CV and 3.3%CV for Levels 1 and 3, respectively. Method comparison for epoc mTCO2 (n = 20) was: mean = 22.9, median = 22.1, r2 = 0.9174, y = 0.9751x + 1.2925. In comparison, method comparison for epoc cTCO2 (n = 20) was: mean = 24.7, median = 23.9, r2 = 0.9165 y = 0.9855x + 2.8559. Conclusion The epoc measured TCO2 studies show better correlation to the Radiometer ABL800 than the epoc calculated cTCO2, and it is considered acceptable for implementation at our Center City sites where epoc is currently in use.