Comparison of blood gas and electrolyte test results from the Gem-Stat and CDI-300 versus a conventional laboratory analyzer.

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, in-line CDI-300 blood gas monitor and the Mallinckrodt Gem-Stat blood gas analyzer using intermittent sampling with the Corning 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 Corning 278 blood gas analyzer results, all measured values (arterial pH, pCO 2, pO 2, venous pO 2, Na, K and Hct) correlated greater than 0.5000 with a p value of less than 0.001. The exception was the ionized calcium value which had a correlation of 0.2473 with a p value of less than 0.232. When comparing the CDI-300 results to the Corning 278 blood gas machine results, all measured values (pH, pO 2, pCO 2, and venous pO 2) correlated greater than 0.5000 with a p value of less than 0.003 or better. When comparing the Gem-Stat results to the CDI results, all measured values (pH, pCO 2, pO 2 and venous pO 2) correlated greater than 0.5000 with a p value of less than 0.002 or better.