RADIOMETER ABL800 FLEX, Reference Manual

Page: 158 / 206

ABL800 FLEX Reference Manual 6. Parameters
Derived parameters,
Continued
Oxygen derived
parameters
(continued)
Symbol Definition Type Eq.
F
Shunt Relative physiological shunt or concentration-
based shunt [5,8,9].
•
Calculated from the pulmonary shunt
equation:
&
&
( )
Q
Q
tO (a v)
tO A tO (a)
s
t
2
2 2
=
+
−
−
1
1
c
c c
if both arterial and mixed venous blood
samples are used.
•
May be estimated from one arterial sample
by assuming a constant difference in the
concentrations of total oxygen in arterial
and mixed venous blood:
c
tO (a v) 2.3 mmol / L (5.1 mL / dL)
2
− =
dv
34
F
Shunt (
T
)
F
Shunt at patient temperature. dv
35
RI Respiratory Index; ratio between the oxygen
tension difference of alveolar air and arterial
blood and the oxygen tension of arterial blood. dv
36
RI(
T
) Respiratory Index; ratio between the oxygen
tension difference of alveolar air and arterial
blood and the oxygen tension of arterial blood at
patient temperature. dv
37
V
O
2
/
V
(dry
air)
Volume fraction of oxygen in dry air. dv
52
Q
x
Cardiac oxygen compensation factor of arterial
blood defined as the factor by which the cardiac
output should increase to allow release of 2.3
mmol/L (5.1 mL/dL) oxygen at a mixed venous
p
O
2
of 5.0 kPa (38 mmHg) [5,8].
dv
38
V
(B) Volume of blood, calculated when
F
COHb and
V
(CO) values are keyed in [5].
dv
42
6-21