Two whole-blood multi-analyte analyzers evaluated

Abstract

We evaluated two multi-analyte analyzers, the NOVA Stat Profile 1 (SP 1) and the NOVA Stat Profile 5 (SP 5). The SP 1 measures pH, (p(CO2), p(O2), sodium, potassium, ionized calcium, and hematocrit in heparinized whole blood; the SP 5 determines all these analytes, plus chloride (not evaluated because it was unavailable at the time this study was initiated) and glucose. Interassay precision for pH, p(CO2), p(O2), sodium, potassium, ionized calcium, and hematocrit (all on the SP 1) and glucose (on the SP 5) was excellent, the respective CVs (%) being: < 0.006, 2.1, ≤ 3.0, ≤ 0.5, ≤ 1.7, ≤ 2.1, ≤ 3.9, and ≤ 1.2. Correlation with results obtained with Corning's Model 178, NOVA Biomedical's Model 6, Beckman's Astra 8, and Roche's Cobas-Bio was also excellent (r > 0.975 for all analyses, r for hematocrit 0.865). Temperature-stability studies on whole-blood specimens maintained at 1 °C indicated that results for all measured analytes were essentially uncharged for at least 2 h, except for potassium, which increased by 13% in 2 h. At 22°C, values for pH, p(CO2), p(O2), and glucose changed significantly within 2 h. Advantages of the NOVA Stat Profile series include decreased specimen requirements (250 μL), analysis time (72-90 s), turnaround time (about 4.5 min), and overall cost of operation.