Clinical evaluation of a new continuous intraarterial blood gas monitoring system in the intensive care setting

Abstract

The present study was designed to evaluate a new continuous intraarterial blood gas monitoring system under routine clinical intensive care conditions. Nine mechanically ventilated adult patients were enrolled in this study. A multiparameter intravascular sensor was inserted into the radial or dorsalis pedis artery through a 20-gauge cannula in each patient. The accuracy of the sensor for pH, Pco2, and Po2 values was evaluated by comparing the data simultaneously obtained from the monitoring system and from conventional blood gas analysis. Measurements were performed for 3 days for each sensor. A total of 62 blood samples were obtained for comparison. The ranges of measured variables were: pH 7.185-7.602, Pco2, 28.8-68.5 mmHg, and Po2 45.2-542.4 mmHg. The overall bias ±precision values were 0.002±0.018 for pH units, 0.53±2.04mmHg for Pco2, and -1.62±20.00 mmHg for Po2. In clinically important ranges of Po2, less than 200 mmHg in particular, the bias and precision values were -2.25±6.48 mmHg in the range of less than 100mmHg, and 0.98±14.38 mmHg in the range of 100-200 mmHg. Variations of sensor accuracy as a function of elapsed time were within the clinically acceptable range throughout the study period. These findings suggest that this new device is sufficiently useful for routine clinical settings.