User's Manual

i15 Blood Gas and Chemistry Analysis System User Manual Theory
- 121 -
BE (ecf)
Base excess (ecf)
BE (ecf) = HCO
3
-
act - 24.8 + (16.2 × (pH - 7.40)) [mmol/L]
BE (B)
Base excess (B)
BE (B) = (1 - 0.014 × tHb (est)) × [HCO
3
-
act - 24.8 + (1.43 × tHb (est) + 7.7) × (pH - 7.40)]
[mmol/L]
Where tHb (est) can be entered by users, and the default value for tHb (est) is 15g/dL.
BB (B)
Buffer Base
BB (B) = BE (B) + 41.7 + 0.42 × tHb (est) [mmol/L]
Where tHb (est) can be entered by users, and the default value for tHb (est) is 15g/dL.
ctCO
2
Total carbon dioxide
ctCO
2
= HCO
3
-
act + 0.0307 × pCO
2
[mmol/L]
Ca
++
(7.4)
The ionized calcium concentration of blood normalized to pH 7.4
Ca
++
(7.4) = Ca
++
× 10
[0.178 × (pH - 7.40)]
[mmol/L]
AnGap
An approximation of the difference between measured cations and measured anions in the sample
AnGap = (Na
+
+ K
+
) - (Cl
-
+ HCO
3
-
act) [mmol/L]
tHb (est)
An estimation of the hemoglobin contained in the sample
tHb (est) = MCHC × Hct / 100 [g/dL]
Where MCHC is the mean corpuscular hemoglobin concentration, and can be entered by users.