Evaluation of a transportable capnometer for monitoring end-tidal carbon dioxide

Anaesthesia. 2010 Oct;65(10):1017-21. doi: 10.1111/j.1365-2044.2010.06499.x.


We compared a small and transportable Capnometer (EMMA™) with a reference capnometer, the Siesta i TS Anaesthesia. During air-breathing through a facemask, both the EMMA (nine modules) and reference capnometer sampled expired gas simultaneously. A wide range of end-tidal carbon dioxide values were obtained during inhalation of carbon dioxide and voluntary hyperventilation. The median IQR [range] difference between all sets of carbon dioxide values (EMMA - reference) was -0.3 (-0.6 to 0.0 [-1.7 to 1.6] kPa; n = 297) using new batteries, which was statistically significant (p = 0.04) and located to two of the nine EMMAs tested. Using batteries with reduced voltage did not influence the measurements. The 95% CI of the medians of the differences were -0.4 to -0.2. We conclude that the EMMA can slightly under-read the end-tidal carbon dioxide but is generally comparable with a free-standing monitor. The precision of the EMMAs was similar whether new batteries or batteries with reduced voltage were used.

Publication types

  • Evaluation Study

MeSH terms

  • Breath Tests / instrumentation
  • Capnography / instrumentation*
  • Carbon Dioxide / analysis*
  • Electric Power Supplies
  • Equipment Design
  • Humans
  • Masks
  • Monitoring, Physiologic / instrumentation*
  • Point-of-Care Systems
  • Reproducibility of Results
  • Transportation of Patients


  • Carbon Dioxide