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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 S O
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
O 00314 . 0 tHb
100
Hb O
39 1 ctO P
⋅ + ⋅ ⋅ = .
[vol%]
9
NOTE: If P
O
2
is not available, ct
O
2
is calculated with P
O
2
= 90 mmHg.
If measured O
2
Hb and tHb are not available and calculated
S
O
2
is enabled:
2
2
2
O 00314 . 0 tHb
100
O
39 . 1 O P
S
t ⋅ + ⋅ ⋅ =
[vol%]
9
NOTE : If
P
O
2
is not available, ct O
2
is calculated with
P
O
2
= 90 mmHg
.
P50
The oxygen partial pressure at half saturation, P 50, is defined as the P O
2
value for a given blood
sample at which 50% of the hemoglobin is saturated with oxygen. While the actual P 50 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 P O
2
held constant at 7.4 and 40 mmHg respectively, the OPTI CCA-
TS allows for the estimation of P 50 from measured S O
2
% , P O
2
and pH. If a measured S O
2
% is
not available, the P 50 value may be input via keypad.
For Adult hemoglobin:
( )
2
2
2
O lg O lg
50
O % 100
O
9 . 2
) 172 . 4 (lg
O lg
:
10 7 . 26
2 2
S
S
Q
Q
where
k
k
−
=
+
=
⋅ =
−
P
P
P P
[mmHg]
6
9 CLSI. Blood Gas and pH Analysis and Related Measurements; Approved Guideline. NCCLS document C46-A,
2001.