Siemens RAPIDLAB 248, Operator'S Manual, Page: 135 / 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 p CO
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 - 0.004 c tHb) x (HCO
3
–
act
- 24) + (9 + 0.3 c tHb) x (pH - 7.4) -
0.3 c tHb x (100 - O
2
SAT)/100
Base Excess of Blood (BE(B))
Formerly BE(vt)
BE(B) = (1 - 0.014 c tHb) x (HCO
3
–
act
- 24) + (9.5 +1.63 c tHb) x (pH - 7.4)
Oxygen Content (O
2
CT)
O
2
CT = 1.39 c tHb x O
2
SAT/100 + 0.003 p O2
Oxygen Saturation (Estimated)
No change
Total Carbon Dioxide (ctCO
2
)
c tCO
2
= 0.031 p CO
2
+ HCO
3
–
act
Patient Temperature Correction
pH(T) = pH - 0.015 x (T - 37)
p CO
2
no change
p O
2
(T) = p O
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