Περίληψη:
The lack of methodology for measuring the alveolar carbon dioxide
tension (PA,CO2) has forced investigators to make several assumptions,
such as that PA,CO2 is equal to end-tidal (PET,CO2) and arterial CO2
tension (Pa,CO2),
The present study measured the mean PA,CO2 and Bohr’s dead space ratio
(Bohr’s dead space/tidal volume( VD,Bohr/VT)) during tidal breathing.
The method used is a new, simple and noninvasive technique, based on the
analysis of the expired CO2 volume per breath (VCO2) versus the exhaled
VT. This curve was analysed in 21 normal, healthy subjects and 35
chronic obstructive pulmonary disease (COPD) patients breathing tidally
through a mouthpiece apparatus in the sitting position.
It is shown that: 1) PA,CO2 is similar to Pa,CO2 in normal subjects,
whilst it is significantly lower than Pa,CO2 in COPD patients; 2) Pa,CO2
is significantly higher than PET,CO2 in all subjects, especially in COPD
patients; 3) VD,Bohr/VT is increased in COPD patients as compared to
normal subjects; and 4) VD,Bohr/VT is lower than the “physiological”
dead space ratio (VD,phys/VT) in COPD patients,
It is concluded that the expired carbon dioxide versus tidal volume
curve is a useful tool for research and clinical work, because it
permits the noninvasive and accurate measurement of Bohr’s dead space
and mean alveolar carbon dioxide tension accurately during spontaneous
breathing.
Συγγραφείς:
Koulouris, NG
Latsi, P
Dimitroulis, J
Jordanoglou, B and
Gaga, M
Jordanoglou, J
