The Science Journal of the American Association for Respiratory Care
Background: The Novametrix CO2SMO Plus Respiratory Profile Monitor is a monitor that profiles the patient's respiratory status with respiratory mechanics, capnography, and oximetry. Hospitals are consistently finding ways to cut health care costs. This clinical study evaluated the correlation of End-Tidal Carbon Dioxide (ETCO2) with Arterial Carbon Dioxide (PCO2) and the Pulse Oximetry Saturation (SPO2) with Arterial Oxygen Saturation (SaO2) in critically ill, mechanically ventilated patients.
Study Question: Does the CO2SMO Plus accurately represent the PCO2 and SaO2 in critically-ill patients?
Methods: Forty five (45) critically-ill, mechanically ventilated patients in the Medical and Surgical ICU were evaluated. Patients were included in the study if they were intubated and routine blood gases were ordered. Arterial blood gases were obtained via indwelling A-lines and arterial puncture technique. A combined mainstream CO2 capnography/flow sensor from the CO2SMO Plus was placed inline between the endotracheal tube and the wye of the ventilator circuit. The pulse oximetry was measured via finger probe from the CO2SMO Plus. Data was collected by Novametrix software generated by LabView (National Instrumentation). The CO2SMO Plus was placed on the patient for a minimum of three (3) minutes prior to an arterial blood gas being drawn. The ETCO2 and SPO2 were recorded at the time of the blood gas draw. The blood gas was placed on ice and transported to the laboratory for analysis using a Chilon Blood Gas Analyzer/Co-Oximeter (Chilon, Inc.). The PCO2 and SaO2 results of the blood gas were then recorded. Only one evaluation per patient per day was completed.
Results: Data was analyzed using the Pearson Correlation Coefficient test to determine the correlation between ETCO2/PCO2 and SPO2 / SaO2. The correlation factor for the SPO2 / SaO2 was +0.91, which is significant at p< .001 when tested against a correlation of 0.00. The correlation factor for the ETCO2/PCO2 was +0.60, which is significant at p < .001 when tested against a correlation of 0.00. A cost savings of $2,511.41 would have been recognized if these 45 patients used the CO2SMO Plus during these evaluations.
Conclusion: Our results indicate that the CO2SMO Plus was able to correlate the SPO2 with SaO2 and the ETCO2 with PCO2 in these 45 critically-ill patients. We conclude that a potential cost benefit from less arterial blood gas procedures can be recognized by utilizing the CO2SMO Plus. More studies must be conducted to differentiate disease process and the response to the CO2SMO Plus.