Background: Cutaneous carbon dioxide tension (PcCO(2)) is a promising non-invasive surrogate measure of arterial partial pressure of carbon dioxide (PaCO(2)).
Objectives: To compare values of PcCO(2) and oxygen saturation (SpO(2)) with arterial blood gas (ABG) analysis.
Methods: SpO(2) and PcCO(2) were measured with a v-Sign-sensor (Sentec AG, Therwil, Switzerland) and the values compared with simultaneously obtained SaO(2) and PaCO(2) obtained from ABG analysis (ABL 725, Radiometer, Copenhagen, Denmark) in 275 adult patients referred to the lung function laboratory.
Results: Median of the PcCO(2) was 4.7 kPa (interquartile range [IQR] 0.9 kPa). Median of the SpO(2) was 97% (IQR 3%). Bland-Altman analysis for comparison of PcCO(2) with PaCO(2) showed a bias of -0.1 kPa with a precision of +/- 0.9 kPa with 3.7% outlying values. Bland-Altman analysis for the comparison of SpO(2) and SaO(2) showed a bias of 20.1 % with a precision of +/- 3.5%. There were no complications.
Conclusion: There is a good agreement between combined cutaneous capnography and oximetry values with ABG analysis. Due to the excellent safety profile and the short time to get a continuous measurement, this technique should be examined in settings where it can complement repeated ABG analysis when ventilatory disturbances are suspected or non-invasive monitoring of ventilation is needed.