Comparison Between The Transcutaneous Carbon Dioxide Tension At The Infraclavicular Site With The Arterial Carbon Dioxide Tension

Background: Transcutaneous measurement of carbon dioxide is routinely done at the earlobe site. In patients receiving non invasive ventilation or in the intensive care setting with necklines, an alternate measurement site would be useful. The infraclavicular site has major blood vessels in its viscinity. We started to use the infraclavicular site for transcutaneous measurements of carbon dioxide using a new digital sensor. Aim: Comparison of transcutaneous carbon dioxide with arterial carbon dioxide at the infraclavicular site. Methods: We retrospectively compared transcutaneous carbon dioxide at the infraclavicular site with arterial carbon dioxide in 50 samples. The Sentec Digital Monitoring System (SentecAG, Therwil, Switzerland) was used. The V-Sign digital sensor was placed on the infraclavicular site at the medial two third and one third point from the sternoclavicular joint and acromioclavicular jont. Results: When comparing PtcCO2 with PaCO2 values, the Bland-Altman analysis revealed a bias of 0.15 mmHg (95% CI: [-0.76; 1.05]) with a precision of 3.18 mmHg. Linear regression analysis describes the relationship between the two methods. The slope of the linear model was 0.85. ± 0.04 and the intercept was 5.78±1.58 (RSE = 2.8, R2 = 0.91). Conclusion: The measurement of transcutaneous carbon dioxide at the infraclavicular site is feasible with a digital sensor and has a good correlation with the carbon dioxide values obtained from the arterial blood gas.