OPTIMedical OPTI CCA-TS - Page 249

A-10 Operator’s Manual – OPTI CCA-TS
APPENDIX A - TECHNICAL SPECIFICATIONS
BE
(act)
Base excess at actual oxygen saturation.
( ) ( ) ( )
[ ]






−⋅⋅−
+−−⋅+⋅⋅⋅
−
100
O
1tHb2.0
HCO26.244.7pH5.9tHb63.1tHb0.0143-1=BE
2
3(act)
S
[mmol/L ]
8
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signicant.
tHb42.0 +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, PCO
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signicanterrorsintheresultingvalue
for those patients who are in the most critical clinical state. The OPTI CCA-TS has the capability
to provide a measured SO
2
from the blood sample. It is recommended that this measured value, if
available, should be used in preference to the calculated SO
2.
If not available from measurement, and if calculation is selected:
5.21
BE0.0013+)
26.7
21.5
lg(-7.4)-(pH0.48OlgOlg
4.113101.3632O lg 2.9=lgQ
:Fetal
26.7
BE0.0013+)
26.7
26.7
lg(-7.4)-(pH0.48OlgOlg
4.172101.661Olg 2.9=lgQ
:Adult
100%
1+Q
Q
%SO
50
2
k
2
O0.0533
k
2
50
2
k
2
O0.074
k
2
2
k
2
k
2
=
⋅⋅+=
−⋅+⋅
=
⋅⋅+=
−⋅+⋅
⋅=
⋅−
⋅−
P
PP
P
P
PP
P
P
P
8
Zander R., Die korrekte Bestimmung des Base Excess (BE mmol/l) im Blut. Anesthesiol. Intensivmed. Notfallmed.
Schmerzther.
(7)
(6)