RADIOMETER ABL90 FLEX - Cto 2; Cto (AV ); Cto (X) (or C )

ABL90 FLEX reference manual 8. Parameters
8-29
Eq. 26 [8]:
The ODC is determined as described in equations 46-47 in the section
Oxyhemoglobin Dissociation Curve further in this chapter.
pO
2
(x) is calculated by a numerical method, using:
Eq. Description See…
26.1 S = ODC(P,A,T) Eq. 47
26.2


2,i
1 MetHb COHb
O
1COHbMetHb
SF F
s
FF
 


Eq. 46.12
26.3

2,i
2,i
P
O
COHb
1
O1COHbMetHb
p
F
sFF


 
Eq. 46.10
26.4


i2,i
2,i
ttHb1COHbMetHbO
+0.0105 O
cFFs
p
  

26.5 A = a
26.6 T = 37 °C
When t
i
= ctO
2
– 2.3 mmol/L, then pO
2,i
= pO
2
(x), where ctO
2
is determined as
described in equation 27.
pO
2
(x) cannot be calculated on the basis of a default ctHb value.
pO
2
(x) can only be calculated if the measured sO
2
(a) 0.97.
The calculation requires entering the sample type as "Arterial" or "Capillary".
Eq. 27 [5]:


2222
tO O O O 1 COHb MetHb tHbcpsFFc      
O
2
is the concentrational solubility coefficient for O
2
in blood (here set to
0.0105 mmol/L/kPa at 37 °C [24].
ctO
2
cannot be calculated on the basis of a default ctHb value.
NOTICE: The formula is different from previous Radiometer analyzers. The
oxygen solubility coefficient is now changed from 0.00983 to 0.0105 to be in
accordance with NCCLS (CLSI)-approved guidelines [24].
The change corresponds to 0.00067 mmol/L/kPa.
Eq. 28:
ctO
2
(a  v
–
) = ctO
2
(a) – ctO
2
(v
–
)
where ctO
2
(a) and
ctO
2
(v
–
) are calculated from equation 27 for arterial and mixed
venous blood, respectively. The calculation requires two measurements and input
of both pO
2
(v
–
) and sO
2
(v
–
).
Eq. 29 [7]:


2
tHb 1 COHb MetHbBO c F F 
BO
2
cannot be calculated on the basis of a default ctHb value.
pO
2
(x)
(or p
x
)
ctO
2
ctO
2
(av
–
)
BO
2