Definition
Standard base excess is an in vivo expression of base excess. It refers to a model of the extracellular fluid where one part of the blood is diluted by two parts of its own plasma. Alternatively, a standard value for the hemoglobin concentration of the total extracellular fluid (including blood) of 3 mmol/L can be used, cBase(Ecf) = cBase(B) for ctHb = 3 mmol/L. The systematic symbol for standard base excess is cBase(Ecf). The analyzer symbol may be SBE or cBase(Ecf).

What does cBase(Ecf) tell you
cBase(Ecf) is the base excess in the total extracellular fluids, of which blood (the intravascular part) represents approx. one third. As buffering capacities differ in the extracellular compartments (i.e., the intravascular vs. the extravascular compartment), cBase(Ecf) is an estimate more representative of in vivo base excess than is BE.

Reference ranges
cBase(Ecf) reference range (adult):
male: -1.5 – (+) 3.0 mmol/L
female: -3.0 – (+) 2.0 mmol/L
disclaimer

Clinical interpretation
Considerations are as for BE, see this.