Performance Evaluation of the i-SmartCare 10 Analyzer and Method Comparison of Six Point-of-Care Blood Gas Analyzers

Abstract

Blood gas, electrolyte, glucose, and lactate level measurement have an immediate and critical impact on patient care. We evaluated the performance of i-SmartCare 10 (i-SENS Inc., Seoul, Korea) and conducted a method comparison study of five point-of-care (POC) analyzers with i-SmartCare 10 as the comparator, according to the CLSI guidelines. Ten analytes (pH, pCO₂, pO₂, Na⁺, K⁺, Cl^-, iCa²⁺, glucose, lactate, and Hct) were tested on six analyzers: i-SmartCare 10, ABL90 FLEX PLUS (Radiometer Medical ApS, Copenhagen, Denmark), i-Stat (Abbott Point of Care Inc., Princeton, NJ, USA), RapidLab 1265 (Siemens Healthcare Diagnostics Inc., Tarrytown, NY, USA), Stat Profile pHOx Ultra (Nova Biomedical, Waltham, MA, USA), and Gem Premier 5000 (Instrumentation Laboratory, Bedford, MA, USA). The total imprecision and linearity (r²>0.99) were excellent, except for a few analytes that narrowly escaped the preset criteria. Interference was noted for Na⁺ in the presence of a high K⁺ level and for iCa²⁺ in the presence of high K⁺ and Mg²⁺ levels. Forty of 48 items demonstrated either a proportional or systematic difference in regression analysis; the relative mean difference (%) of 14/48 items escaped the allowable total error in the difference plot analysis. i-SmartCare 10 shows acceptable performance, and using a single POC blood gas analyzer is recommended for monitoring.

Keywords: Analytical performance evaluation; Blood gas analyzer; Method comparison; Point-of-care; i-SmartCare 10.

Fig. 1

Passing–Bablok regression (A) and Bland–Altman difference (B) plots of i-SmartCare 10 (test analyzer) and Gem Premier 5000 (comparator) for hematocrit. In the Passing–Bablok regression plot (A), the solid and dashed lines represent the regression line and its 95% confidence interval, respectively. The dotted line represents the identity line (y=x). In the Bland–Altman difference plot (B), the y-axis represents the relative mean difference (%) of results obtained with the test analyzer and comparator, and the x-axis represents their average value. The solid and dot-dashed line represent the relative mean difference (%) and its 95% CI, respectively. The dashed and dotted line represent the limit of agreement (±1.96 SD of the differences) and y=0, respectively.