Transcutaneous Monitoring of Carbon Dioxide Tension during Lung Volume Reduction Surgery

We used transcutaneous monitoring of carbon dioxide tension for two patients undergoing LVRS and compared of transcutaneous, end-tidal and arterial measurements of carbon dioxide (PtcCO2, PETCO2 and PaCO2). The PaCO2 of each patient was high, 52-91mmHg and 46-60mmHg, respectively. The PETCO2-PaCO2 gradients of these patients were 10-35mmHg and 7-15mmHg, respectively. However, the PtcCO2-PaCO2 gradients of these patients were smaller and within 5mmHg of each other. PtcCO2 monitoring cannot take the place of PETCO2 because it can not show the change in each breath. But these results show that PtcCO2 monitoring is more useful than PETCO2 for patients with ventilation-perfusion mismatching, such as during LVRS.