2003 OPEN FORUM Abstracts
COMPARISON BETWEEN BAYER DIAGNOSTICS RAPIDLAB 865 ARTERIAL BLOOD GAS ANALYZER AND NOVAMETRIX NONINVASIVE CARDIAC OUTPUT MONITOR (NICO)
Sally Whitten, RRT, Steven Desjardins, RRT. Maine Medical Center, Portland, Me.
Background: Arterial Carbon Dioxide (PCO2) provides valuable information for the management of mechanically ventilated patients in the critical care setting. Recent technological advances make such analysis possible without the need of acquiring an arterial blood gas. This study compared the arterial PCO2 acquired from the Diagnostics Rapidlab 865 Blood Gas Analyzer to the Breath by breath volumetric CO2 monitor developed by Novametrix utilizing the Noninvasive Cardiac Output Monitor. (NICO)
Method: PCO2 measurements were obtained from 45 intubated patients in the Critical Care Unit (CCU) and Coronary Recovery Unit (CRU) at Maine Medical Center. Arterial blood gases were drawn from indwelling arterial lines. A combined mainstream CO2 capnography/flow sensor from the NICO monitor was placed in-line between the endotracheal tube and the wye of the ventilator circuit. The CO2 sensor was calibrated utilizing the self-test feature included with the monitor. The sensor was placed in-line for a minimum of five minutes prior to values being recorded for study evaluation. An average of five CO2 values were obtained with the mean CO2 used as our overall data point. An arterial blood gas was drawn after the mean CO2 was determined, and the blood sample was then sent to the lab for analysis.
Results: Forty-five patient measurements were obtained and compared utilizing Bland/Altman statistical analysis. The average mean CO2 (ABG) was 38.8; the average CO2 (NICO) was 37.8 with a mean difference of 1.0 (p=0.6, students T test)
Conclusion: We conclude the NICO system to be an accurate and reliable alternative to repeated arterial blood gas sampling. Statistically, there is no difference between arterial carbon dioxide (CO2) analysis and the NICO monitoring system. Rapid availability of clinical data is beneficial to the clinician for early detection of tissue hypo-perfusion and assessment of the patient's clinical status.