OPTIMedical OPTI CCA-TS - Page 250

Operator’s Manual – OPTI CCA-TS A-11
APPENDIX A - TECHNICAL SPECIFICATIONS
ctO
2
Oxygen content is the sum of oxygen bound to hemoglobin as O
2
Hb and the amount of oxygen
dissolved in the plasma. This value is calculated from the measured O
2
Hb and tHb if available
and is estimated from the calculated SO
2
if the measured O
2
Hb is not available and if the calcula-
tion of oxygen saturation is selected.
If measured O
2
Hb and tHb are available:
2
2
2
O00314.0tHb
100
HbO
391ctO P⋅+⋅⋅= .
[vol%]
9
NOTE: If PO
2
is not available, ctO
2
is calculated with PO
2
= 90 mmHg.
If measured O
2
Hb and tHb are not available and calculated SO
2
is enabled:
2
2
2
O00314.0tHb
100
O
39.1O P
S
t ⋅+⋅⋅=
[vol%]
9
NOTE: If PO
2
is not available, ctO
2
is calculated with PO
2
= 90 mmHg.
P50
The oxygen partial pressure at half saturation, P
50,isdenedasthePO
2
value for a given blood
sample at which 50% of the hemoglobin is saturated with oxygen. While the actual P50 value can
only be determined by interpolation after measurement of oxygen saturation of a blood specimen
tonometered to levels of oxygen to provide an oxyhemoglobin slightly greater than and slightly
less than 50% with pH and PO
2
held constant at 7.4 and 40 mmHg respectively, the OPTI CCA-
TS allows for the estimation of P50 from measured SO
2
% , PO
2
and pH. If a measured SO
2
% is
not available, the P50 value may be input via keypad.
For Adult hemoglobin:
( )
2
2
2
OlgOlg
50
O%100
O
9.2
)172.4(lg
Olg
:
107.26
22
S
S
Q
Q
where
k
k
−
=
+
=
⋅=
−
P
P
PP
[mmHg]
6
9
CLSI. Blood Gas and pH Analysis and Related Measurements; Approved Guideline. NCCLS document C46-A,
2001.