I can't say that capnometers are MORE reliable than blood gases, but when
calibrated properly, they are an ACCURATE reflection of what the
individual's expired CO2 level is. My daughter does NOT have either
monitoring system for home use. I wish she/we did. We do have the
opportunity to use both systems occasionally.
The capnometer is noninvasive. In Kristen's case it measures her end tidal
CO2 by nasal cannula. Unventilated Kristen's end tidal CO2 levels run
45-65, ventilated her CO2 runs 35-40. There is also an adapter that allows
the unit to be used with a trach. The system costs between $2,500-$3,500
(which includes the callibration system). A capnometer is always used when
Kristen is in the sleep lab or PICU. Kristen rarely has blood gases run
(we've actually seen more discrepency/variability with blood gases ie split
samples-differing values). Almost all of her management is done
noninvasively.
Approximately 75% of the families parenting children with CCHS have
capnometers at home and use them regularly. None of the families surveyed
for a research study last year reported problems with this particular
equipment. They seem reliable and durable.
Joanne Kocourek
The University of Chicago
jskocour(AT)midway.uchicago.edu