Comparison of Blood Gas and Electrolyte Test Results From the Gem-Stat and CDI-300 Versus a Conventional Laboratory Analyzer

Abstract

Continuous blood gas monitoring devices have been an aid to the perfusionist since the introduction of the oxygen saturation meters of the early 1980s. Since that time, the perfusionist has had to decide between continuous versus intermittent sampling, and on-line (an analyzer that can automatically sample either at prescribed intervals and/or on demand) versus in-line devices (monitors that continuously sample and display results). This report compares the continuous, inline CDI-300 blood gas monitor and the Mallinckrodt Gem-Stat blood gas analyzer using intermittent sampling with the Coming 278 blood gas analyzer and 2500 Co-Oximeter. Thirty samples were taken, one per 30 patients, for comparison. Five samples were disqualified from the study. When comparing the remaining 25, the Gem-Stat results to the Coming 278 blood gas analyzer results, all measured values (arterial pH, pCO2, pO2, venous pO2, Na, K and Hct) correlated >0.5000 with a p value of <0.001. The exception was the ionized calcium value which had a correlation of0.2473 with a p value of <0.232. When comparing the CDI-300 results to the Coming 278 blood gas machine results, all measured values (pH, pO2, pCO2 and venous pO2) correlated >0.5000 with a p value of <0.003 or better. When comparing the Gem-Stat results to the CDI results, all measured values (pH, pCO2, pO2 and venous pO2) correlated >0.5000 with a p value of <0.002 or better.