Article Text

Download PDFPDF
Validation study of a transcutaneous carbon dioxide monitor in patients in the emergency department
  1. J McVicar1,
  2. R Eager2
  1. 1
    Royal Liverpool University Hospital, Liverpool, UK
  2. 2
    Midland Regional Hospital, Tullamore, Ireland
  1. Dr J McVicar, Royal Liverpool University Hospital, Prescot Street, Liverpool L7 8XP, UK; jane.mcvicar{at}


Background: Transcutaneous carbon dioxide tension (TcPco2) monitors offer a non-invasive method of continuously measuring arterial carbon dioxide tensions. The concordance between the TcPco2 measurement and the value obtained from arterial blood gas sampling (Paco2) was measured in patients attending the emergency department.

Methods: A prospective observational cohort study was performed in 49 adult patients who were undergoing arterial blood gas sampling as part of their assessment. Blood gas sampling and recording of the TcPco2 level from the monitor was done simultaneously. Concordance between the two values (Paco2 and TcPco2) was demonstrated using the method described by Bland and Altman.

Results: The mean difference was 0.02 kPa (95% CI −0.11 to 0.15). The Pearson’s correlation coefficient was 0.94 (p<0.001) and the Bland-Altman limits of agreement were ±0.9 kPa.

Conclusions: In adult patients, concordance between carbon dioxide measurements by transcutaneous monitor and arterial blood sampling is good. Using the transcutaneous method, patients may be monitored non-invasively which may reduce the need for repeated blood gas sampling.

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.


  • Competing interests: None.

  • Ethics approval: The Mersey regional ethics committee approved the study. Written informed consent was obtained from each patient prior to enrolment.