Infraclavicular sensor site: a new promising site for transcutaneous capnography

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. We started to use the infraclavicular site for transcutaneous measurements of carbon dioxide using a new digital sensor.

Comparison of transcutaneous carbon dioxide with arterial carbon dioxide at the infraclavicular site.

We retrospectively compared transcutaneous carbon dioxide at the infraclavicular site with arterial carbon dioxide in 50 samples. The Sentec Digital Monitoring System (Sentec AG, 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 joint.

When comparing P(c)CO(2) with P(a)CO(2) values, the Bland-Altman analysis revealed a bias of 0.02 kPa (95% CI: [- 0.1; 0.14]) with a precision of 0.42 kPa. 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 0.77 ± 0.21 (RSE = 0.37, R(2) = 0.91).

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. The findings of the current study form the basis for further clinical studies for its regular application in clinical use.