Accuracy of portable quantitative capnometers and capnographs under prehospital conditions.

This study was designed to assess the pCO(2) accuracy of portable mainstream (Tidal Wave, Novametrix; Propaq 106, Protocol) and sidestream capnometers (Capnocheck 8200, BCI; Capnocount mini, Weinmann; NPB-75, Nellcor Puritan Bennett; SC-210, Pryon) with respect to international standards and preclinical emergency conditions. Measurements were performed under temperature conditions of +22 degrees C and -20 degrees C using dry gas mixtures with different CO(2) concentrations (STPD) and in patients ventilated with pure oxygen (BTPS). Accuracy presented to be between +1% (Capnocheck) and +12% (Propaq) (STPD) and between -0.4% (Capnocheck) and +11% (Tidal Wave) (BTPS). The measurements were affected by low ambient temperature only in the NPB-75 (+15%). Our results indicate that portable quantitative capnometers are able to fulfill accuracy requirements as requested by international standards but can be affected by changing ambient temperatures.