Calculations
190
Instructions for use – Infinity Acute Care System – Monitoring Applications VG6.n
The Cockpit uses the values in the preceding table, the laboratory values, and the BSA value to calculate
the following derived oxygenation and ventilation parameter values.
Label
Description
Derivation
Available
units
C(a-v)O2
Arteriovenous oxygen dif-
ference
CaO2 – CvO2
mL/dL
CaO2
Arterial oxygen content
0.0134 x Hgb x SaO2
mL/dL
Cdyn
Dynamic compliance
VTe / (PIP – PEEP)
mL/cmH
2
Cs
Static lung compliance
VTe / (Pplat – PEEP) or
VTe / (Pplat – PEEP)
mL/cmH
2
CvO2
Venous oxygen content
0.0134 x Hgb x SvO2
mL/dL
DO2
Oxygen delivery
10 x CaO2 x C.O.
mL/min
DO2I
Oxygen index
10 x CaO2 x CI
DO2 / BSA
mL/min/m
2
MValv
Alveolar minute volume
(VTe – TVd phy) x RR
mL/min
MVe
Expired minute volume
(VTe x RR) / 1000
L/min
MV/C.O.
Ventilation cardiac output
ratio
MValv / C.O.
No units
O2ER
Oxygen extraction ratio
(CaO2 – CvO2) / CaO2
No units
P(A-a)O2
Alveolar-arterial oxygen
difference
iO2 x (Pb –47) – PaCO2 – PaO2
iO2 / 100 x (Pb-47) – PaCO2 – PaO2
mmHg
Qs/Qt
Intrapulmonary right-left
shunt (percentage shunt)
%
TVd phy
Tidal volume dead space
(physiological)
VTe x (1 – PeCO2 / PaCO2)
mL
TVd/TV phy Ratio of tidal volume dead
space to tidal volume dead
space (physiological)
TVd phy / VTe
No units
VO2
Oxygen consumption
10 x C(a-v)O2 x C.O.
mL/min
VO2I
Oxygen consumption in-
dex
10 x C(a-v)O2 x CI
VO2 / BSA
mL/min/m
2
NOTE:
When multiple sources are available, the RR order of priority is RR, RRc, RRi.
Hgb 1.34 0.0031 PAaO2 CaO2
–
×
+
×
Hgb 1.34 0.0031 PaO2 CvO2
–
×
+
×
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×
