2006 OPEN FORUM Abstracts
EVALUATION OF A COMBINED PULSE OXIMETRY AND TRANSCUTANEOUS CARBON DIOXIDE PARTIAL PRESSURE MONITORING SENSOR IN CRITICALLY ILL PATIENTS
Joe Hylton, RRT2, W. Miles, MD1,
C. Funderburk, RRT2 Department of Surgery1 and
Respiratory Care2Carolinas Medical Center, Charlotte, NC
Background: This study evaluates the consistency, accuracy, and ease of use of a commercially available, combination transcutaneous PCO2 (TcPCO2) and pulse oximetry (TcSpO2) sensor placed on the ear lobe of patients. The sensor is designed to measure both relevant oxygenation (SpO2) and ventilation (PCO2) parameters in one single probe.
Methods: The Radiometer TOSCA 500 sensor probe was placed on the patient. Measurements of transcutaneous Pc02 (TcPc02) and Pulse Oximetry (TcSp02) were performed and compared to arterial blood gas samples and standard finger probe Sp02 pulse oximetry measurements at 15 minutes. All measurements were recorded at the time of obtaining the ABG sample. Descriptive statistics (means, standard deviation, accounts, and percentages) were performed for analysis.
Results: There were 32 patients (12 female/20 male) with a mean age of 49 years (range 1d - 78 yrs) admitted to a major tertiary medical center. There were 13 trauma patients (41%), 13 medical patients (41%), 3 surgical patients (9%), 1 cardiac patient (3%), 1 pediatric patient (3%) and 1 neonatal patient (3%). Thirty (94%) of the patients were mechanically ventilated. Two patients (6%) were on supplemental oxygen. Seventeen patients (47%) required pressors to augment mean arterial pressure. A total of 32 measurements were obtained. Mean values were consistent when compared (TcPCO2 = 46.8 ± 14, PaCO2 = 46.2 ± 15; TcSp02 = 96.8% ± 4%, Sp02 = 96.1% ± 5%). When TcPCO2 measurements were compared to PaCO2, 29 measurements (91%) fell within 5 mmHg of the ABG PaCO2 and the majority of measurements (24 samples, 75%) fell within 3 mmHg as compared to the ABG PaCO2. When TcSp02 measurements were compared to Sp02, 28 measurements (88%) fell within 3% of the SpO2 displayed on the ICU monitor. Users of the device all stated there were no difficulties in using the device.
Conclusion: This study shows that TcPCO2/TcSpO2 measured with the Radiometer TOSCA 500 ear sensor showed close correlation with measurements of PCO2 and SpO2 in critically ill patients. This monitor is easy to use and appears suitable for CO2 monitoring and Sp02 monitoring regardless of the mode of ventilation.