Analytical performance of a portable critical care blood gas analyzer.

The portable blood gas analyzer OPTI Critical Care Analyzer was evaluated in comparison to routine laboratory assays using heparinized blood samples of adults and newborns. Within-run imprecision studies were performed with native blood using tonometry to adjust blood gas concentrations. The results obtained show a very close agreement between the OPTI system and the comparison methods for all parameters tested: hemoglobin (y=1.00x-0.2 g/l, r=0.997, n=81), sodium (y=1.13x-18.7 mmol/l, r=0.951, n=79), potassium (y=1.03x-0.04 mmol/l, r=0.972, n=79), pH (y=1.03x-0.29, r=0.958, n=57), pCO2 (y=1.03x-1.14 mm Hg, r=0.988, n=57) and pO2 (y=1.07x-0.85 mm Hg, r=0.995, n=57). The coefficients of variation for the within-run imprecision were below 1.1% for sodium and hemoglobin, and below 2.6% for all other parameters, except for pCO(2) with coefficients of variation up to 3.6% at low calibration gas concentrations. Due to this analytical performance and its portability, the OPTI system is well suited for low to medium test frequencies and immediate use in emergency rooms, intensive care or surgery units.