The aim of this study is calibrate (adjust and tune) the CAS FORE-SIGHT Near-Infrared Spectroscopy (NIRS) monitor when used to measure the tissue oxygen saturation of internal organs (StO2). This is a measure of the amount of oxygen carried by the blood within the internal organs. In addition the study will assess the degree of similarities between StO2 and mean mixed venous oxygen saturation - a measure of the amount of oxygen carried in the blood returning to the heart.
NIRS cerebral oximeters are FDA-approved devices used to measure oxygen saturation within the brain, in a similar manner to pulse oximeters that measure the oxygen saturation in the finger tip. The sensor pads are placed on the surface of the forehead and shine near-infrared light through the skull and brain tissue from which the brain tissue oxygen saturation is estimated. The same principles can be applied when the sensor pads are placed over the internal organs of the abdomen, for example, the liver. Currently the only way to accurately measure the oxygen saturation of internal organs is by the invasive placement of intravenous lines into the blood vessels of that organ. This study will determine if the NIRS sensors can reliably estimate the tissue oxygen saturation non-invasively by placing the pad over the skin of the abdomen. The study will be conducted in pediatric patients who are undergoing cardiac catheterization, a procedure in which invasive lines are placed in order to get information about the heart. The procedure is always conducted under general anesthesia. During the cardiac catheterization procedure blood samples are routinely taken for oxygen saturation analysis. In the study two oximeter sensor pads will be placed on the forehead (one on each side) and two further oximeter sensor pads will be placed on the abdominal wall. The oxygen saturation values from all oximeter sensors will be recorded continuously throughout the cardiac catheterization procedure and will be compared to the oxygen saturation values from the blood samples. In addition to the routine blood samples taken as part of the cardiac catheterization, one blood sample will be taken when the invasive line is within the right hepatic (liver) vein. The information from this study will determine how well the oximeter sensors estimate the oxygen saturation of both the internal organs (StO2) and the blood returning to the heart (mean mixed venous oxygen saturation).
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
DIAGNOSTIC
Masking
NONE
Enrollment
72
Comparison of non-invasive tissue oxygen saturation with blood sample-derived (calculated) tissue oxygen saturation.
Duke University Health System
Durham, North Carolina, United States
Accuracy of NIRS Sensor to Estimate Flank Tissue Oxygen Saturation
The flank tissue oxygen saturation (%) is determined from simultaneous arterial and venous blood samples processed through a blood gas machine. The blood oxygen saturation of the samples are entered into an equation to yield the best estimate of flank tissue oxygen saturation. This value is then compared to the NIRS oxygen saturation (%) displayed on the monitor. Accuracy is used to describe how close the NIRS oxygen saturation is to the flank tissue oxygen saturation. It can be expressed in terms of shots on target: bias (%) = how close are the shots to the bulls eye and precision (%) is how close are the shots to each other. oxygen saturation when measured displayed NIRS value of the tissue sensor placed over the flank to a reference CO-oximetry model, reported as bias and precision. The model is weighted as 30:70 arterial: central venous oxygen saturation when measured by blood gas co-oximetry.
Time frame: Data collected from individual participants over 4 hour timeframe.
Accuracy of NIRS Sensor to Estimate Intestine Tissue Oxygen Saturation
The intestine tissue oxygen saturation (%) is determined from simultaneous arterial and venous blood samples processed through a blood gas machine. The blood oxygen saturation of the samples are entered into an equation to yield the best estimate of intestine tissue oxygen saturation. This value is then compared to the NIRS oxygen saturation (%) displayed on the monitor. Accuracy is used to describe how close the NIRS oxygen saturation is to the intestine tissue oxygen saturation. It can be expressed in terms of shots on target: bias (%) = how close are the shots to the bulls eye and precision (%) is how close are the shots to each other.
Time frame: Data collected from individual participants over 4 hour timeframe.
Accuracy of NIRS Sensor to Estimate Hepatic Tissue Oxygen Saturation
The hepatic tissue oxygen saturation (%) is determined from simultaneous arterial and venous blood samples processed through a blood gas machine. The blood oxygen saturation of the samples are entered into an equation to yield the best estimate of hepatic tissue oxygen saturation. This value is then compared to the NIRS oxygen saturation (%) displayed on the monitor. Accuracy is used to describe how close the NIRS oxygen saturation is to the hepatic tissue oxygen saturation. It can be expressed in terms of shots on target: bias (%) = how close are the shots to the bulls eye and precision (%) is how close are the shots to each other.
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Time frame: Data collected from individual participants over 4 hour timeframe.
Correlation Between Somatic StO2 and Cerebral SctO2 Oxygen Saturation
Time frame: Data collected from individual participants over 4 hour timeframe
Correlation Between NIRS Derived Estimate of Hemoglobin Concentration and Measured Arterial Blood Hemoglobin Concentration.
Time frame: Data collected from individual participants over 4 hour timeframe