Clinical evaluation of the CDI-100 in-line hematocrit/saturation monitor.

This study was undertaken to evaluate the accuracy, reliability, consistency and biases of the CDI-100 saturation monitor when compared with a blood gas analyzer. The advantage of continuous in-line monitoring is that the perfusionist has continuous updates as to the patient's changing physiologic state. During this study, if the sample readout of the CDI-100 was off by greater than 10% from that of the Gem-Premier, the CDI-100 parameter was recalibrated. The accuracy of the CDI-100 was fair (greater than 10% of the samples needed recalibration) with regards to the initial sample comparisons. Recalibration was needed 67% of the time for the hematocrit and 35% for the saturation. The reliability of the CDI-100 was good (no equipment failure). The CDI-100 was consistent. It consistently overestimated both the hematocrit and saturation. This overestimation is the bias of the monitor. We recommend recalibration of the CDI-100 during clinical use to insure greater accuracy.

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.