Narrowing the Gap between the Anion Gap and the Strong Ion Gap-Juniper Publishers
Juniper Publishers - Journal of Anesthesia Abstract Background: Despite its importance in understanding acid-base pathophysiology, many physicians do not comprehend the concept of the strong anion gap (SIG), the core of the Stewart acid-base approach. The quantitative difference between the anion gap and the strong ion gap is not established. This paper will give insight into this difference over a variety of conditions Methods. The empiric difference between the SIG and the albumin-corrected anion gap (AGc) was calculated at a wide range of albumin, phosphorus and pH levels. Results: At an albumin level of 1-3 g/dl and pH from 6.9-7.3, the contribution difference of albumin between the AG c and the SIG will be maximally -0.97 to 0.51mEq/L. In metabolic alkalosis and hypoalbuminaemia, the AG c differs less than 2mEq/L from the SIG. The calculated contribution of phosphorus is higher in the SIG with phosphorus levels >2mmol/L and can be accounted for in the a...