Abstract
Background: Cutaneous carbon dioxide tension (PcCO2) is a promising non-invasive surrogate measure of arterial partial pressure of carbon dioxide (PaCO2). Objectives: To compare values of PcCO2 and oxygen saturation (SpO2) with arterial blood gas (ABG) analysis. Methods: SpO2 and PcCO2 were measured with a v-Sign™-sensor (Sentec AG, Therwil, Switzerland) and the values compared with simultaneously obtained SaO2 and PaCO2 obtained from ABG analysis (ABL 725, Radiometer, Copenhagen, Denmark) in 275 adult patients referred to the lung function laboratory. Results: Median of the PcCO2 was 4.7 kPa (interquartile range [IQR] 0.9 kPa). Median of the SpO2 was 97% (IQR 3%). Bland-Altman analysis for comparison of PcCO2 with PaCO2 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 SpO2 and SaO2 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.
Declaration of interest: Prashant N. Chhajed is on the medical advisory board of Sentec AG.