OPTi CCA-TS2, Руководство оператора, Страница: 282 / 299

A-10 Operator’s Manual – OPTI CCA-TS2
APPENDIX A - TECHNICAL SPECIFICATIONS
BB
The buffer base is the concentration of buffering anions which is available in whole blood to
buffer strong acids and consists mainly of protein anions and bicarbonate. Of the protein anions,
hemoglobin is the most significant.
tHb 42 . 0 + 7 . 41 + BE = BB ⋅
[mmol/L]
6
SO
2
(c)
The oxygen-hemoglobin dissociation curve theoretically allows that oxygen saturation of
available hemoglobin can be calculated, provided the form of the curve is known. Factors
which are known to affect this curve include: hemoglobin species, pH, P CO
2
, temperature
and 2,3 diphosphoglycerate (2,3 DPG) content. Although it is possible to calculate this value,
the assumptions which are made in the calculation can cause significant errors in the resulting
value for those patients who are in the most critical clinical state. The OPTI CCA-TS2 has
the capability to provide a measured
S
O
2
from the blood sample. It is recommended that this
measured value, if available, should be used in preference to the calculated S O
2.
If not available from measurement, and if calculation is selected:
5 . 21
BE 0.0013 + )
26.7
21.5
lg( - 7.4) - (pH 0.48 O lg O lg
4.113 10 1.3632 O lg 2.9 = lgQ
: Fetal
26.7
BE 0.0013 + )
26.7
26.7
lg( - 7.4) - (pH 0.48 O lg O lg
4.172 10 1.661 O lg 2.9 = lgQ
: Adult
100%
1 + Q
Q
% SO
50
2
k
2
O 0.0533
k
2
50
2
k
2
O 0.074
k
2
2
k
2
k
2
=
⋅ ⋅ + =
− ⋅ + ⋅
=
⋅ ⋅ + =
− ⋅ + ⋅
⋅ =
⋅ −
⋅ −
P
P P
P
P
P P
P
P
P
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%]
7
NOTE: If P
O
2
is not available, ct
O
2
is calculated with P
O
2
= 90 mmHg.
(7)
(6)