Table 1

 Equations and definitions

Definition
Metabolic acidosisSB <22 mmol/l
Corrected chloride (cCl)140 × Cl/Na
HyperchloraemiacCl >110 mmol/l
Raised lactate>2 mmol/l
Raised SIG>2 mmol/l
Low albumin<30 g/l
SIDcNa + K + Ca + Mg – (Cl + lactate)
SIDeBicarbonate + PO4 charge + albumin charge
Strong ion gap (SIG)SIDc – SIDe