CareFusion AVEA - Page 248

234 Appendix I: Volumetric CO2 Calculations Operator's manual
L2786 Rev. M
FeCO
2
Percentage of carbon dioxide in the exhaled gas reported by the CO
2
sensor at the wye. This
value is used in the dead space calculations but is not displayed.
PeCO
2
Mean exhaled partial pressure of carbon dioxide in the exhaled gas reported by the CO
2
sensor at the wye. This value is used in the dead space calculations but is not displayed.
Physiologic Dead Space (Vd phy)
Comprises anatomic dead space (see below) as well as the volume of the respiratory zone
(respiratory bronchioles, alveolar ducts and alveoli) not participating in gas exchange. The
classic Bohr-Enghoff
2
equation is used to calculate physiologic dead space. This method uses
arterial CO
2
(PaCO
2
) as an estimator for alveolar CO
2
(PACO
2
).
Physiologic Dead Space / Tidal volume ratio (Vd phy / Vt)
Used to calculate the ratio of the tidal volume not participating in gas exchange (wasted
ventilation).
2
Enghoff H: Volumen inefficax: Bemerkungen zur Frage des schadlichen Raumes. Upsalla Lakareforen Forhandl, 1938;
44:191-218.