The accuracy of the i-STAT portable analyser for measuring blood gases and pH in whole-blood samples from dogs

To assess the suitability of the i-STAT portable analyser for use by non-laboratory personnel, we measured blood gases and pH in venous blood samples from 100 dogs. Deming's regression and bias plots were used to compare i-STAT results with those obtained by laboratory professionals using two different autocalibrated benchtop analysers. Overall accuracy of the portable analyser proved excellent for pH, pO 2, and pCO 2 ( r=0.978, 0.968 and 0.997, respectively), with Deming's regression slopes close to 1.00 (0.96, 0.97 and 1.08 for pH, pO 2, and pCO 2, respectively) and intercepts close to zero (0.28, 0.47 kPa and 0.46 kPa for pH, pO 2, and pCO 2, respectively). The accuracy of the i-STAT was also satisfactory for calculated parameters: bicarbonates, total CO 2, base excess and oxygen saturation. Our findings show this portable analyser to be a valid substitute for expensive benchtop analysers in situations requiring mobility, or when small numbers of tests are to be performed by users not specialized in laboratory techniques.