Step 4

Step 4:

Delta-delta or Gap-gap is a measure to see whether the change in bicarbonate is roughly the same as the change in anion gap. If the change is not roughly equal then there is an additional acid base disorder.

delta[AG]-delta[HCO3] IF >6 metabolic alkalosis: IF <-6 hyperchloremic metabolic acidosis

OR the ratio method is

delta[AG]/delta[HCO3]>2 is metabolic alkalosis, 1-2 is HAGMA, 0.4-0.8 possible mixed HAGMA AND NAGMA, <0.4 NAGMA

(DEFINITION: delta[AG]= Actual AG-12  delta[HCO3]= Actual bicarbonate-24)