Siemens RAPIDLAB 248 - Page 135

248 Operator’s Manual Page G-11
The algorithms used for Calculated Parameters are those currently
recommended by NCCLS. Algorithms used in our earlier instruments
are given here for reference:
Actual Bicarbonate (HCO
3
–
act)
HCO
3
–
act
= 0.031 x pCO
2
x 10
(pH - 6.1)
Standard Bicarbonate (HCO
3
–
std)
No change
Base Excess of Extracellular Fluid (BE(ecf))
Formerly BE(vv)
BE(ecf) = (1 - 0.004ctHb) x (HCO
3
–
act
- 24) + (9 + 0.3ctHb) x (pH - 7.4) -
0.3ctHb x (100 - O
2
SAT)/100
Base Excess of Blood (BE(B))
Formerly BE(vt)
BE(B) = (1 - 0.014ctHb) x (HCO
3
–
act
- 24) + (9.5 +1.63ctHb) x (pH - 7.4)
Oxygen Content (O
2
CT)
O
2
CT = 1.39ctHb x O
2
SAT/100 + 0.003 pO2
Oxygen Saturation (Estimated)
No change
Total Carbon Dioxide (ctCO
2
)
ctCO
2
= 0.031pCO
2
+ HCO
3
–
act
Patient Temperature Correction
pH(T) = pH - 0.015 x (T - 37)
pCO
2
no change
pO
2
(T) = pO
2
x 10
(A x (T - 37))
where A = 0.0052 + 0.027 x (1 - 10
(–0.13 x (100 - O
2
SAT))
)
Arterial-Alveolar Oxygen Tension Difference
No change
Arterial-Alveolar Oxygen Tension Ratio
No change