Roche cobas b 123 - Heart Minute Volume (Q T ); Oer; PF Index

Roche Diagnostics
110 Instructions for Use · Version 13.0
4 Theoretical foundations cobas b 123 POC system
Parameters and calculations
Equation 4-46
q
Osm
opt
Gap is only calculated if the input value, Osm(e) (measured osmolality with an
osmometer) and the calculated value, Osm
opt
, are available.
OER
Oxygen extraction ratio.
[1]
Unit: [%]
Equation 4-47
u ctO
2
(p. 101)
Calculating OER requires the following conditions:
o Same patient numbers for both measurements
o 2 consecutive measurements
o Sample type is arterial and mixed venous blood
q
Different OER calculations are used, depending on whether measured COOX values are
available or not.
If you have a measured O
2
Hb value, the X parameter in the ctO
2
formula is the O
2
Hb value.
If you do not have a measured O
2
Hb value, the X parameter in the ctO
2
formula is SO
2
(c).
Heart minute volume (Q
t
)
Unit: [vol%]
[6]
Equation 4-48
SaO
2
: arterial oxygen saturation fraction
ctO
2
(a) - ctO
2
(v) = avDO
2
Calculating Qt requires the following conditions:
o Same patient numbers for both measurements
o 2 consecutive measurements
o Sample type is arterial and mixed venous blood
PF index
Ratio of alveolar oxygen partial pressure to the proportion on inspiratory oxygen
[6]
Unit: [mm/Hg]
ܱݏ݉
opt
ܩܽ݌ = ܱݏ݉
(
݁
)
െܱݏ݉
opt
100
tO
)tOtO(
OER
2(a)
2(v)2(a)
⋅
−
=
c
cc
0.00314])aOAO()
100
aO
(1tHb1.39(v))tO(a)tO[(
ctO (C) ctO (v)
Q
22
2
22
t
⋅−+−⋅⋅+−=
−=
PP
S
cc
22