Question

In patients with severe hypoalbuminemia, an AG acidosis can exist even when a normal AG is measured. In such patients, the expected AG may be as low as 4 to 5 mmol/L.

For every albumin decrease of 1 g/dL, a decrease of 2.5 to 3 mmol in AG will occur.
The corrected AG can be calculated using the following formula:

AGcorrected = AGobserved + 2.5 x [normal albumin-measured albumin (in g/dL)]

Answer 1

Severe hypoalbuminemia can cause a falsely normal anion gap, which is corrected by accounting for albumin levels in the AG calculation. An altered AG reflects changes in the electrolyte balance that can have significant clinical implications, such as metabolic acidosis, which involves reduced blood bicarbonate levels.

Step-by-step explanation:

In patients with severe hypoalbuminemia, the anion gap (AG) can be falsely normal due to the reduced level of albumin. Since albumin is a negatively charged protein, its reduction leads to a decreased anion gap. To correct this, the AG can be adjusted for albumin levels using the following formula:

AGcorrected = AGobserved + 2.5 x [normal albumin - measured albumin (in g/dL)]

For every gram per deciliter decrease in albumin, there is a concomitant decrease of 2.5 to 3 mmol/L in the anion gap. Considering that the normal albumin/globulin (A/G) ratio averages to 1.5 and globulin concentration ranges from 2-5 g/dL, a decreased A/G ratio indicates a decreased albumin level. It is important to note that acidosis and alkalosis can have significant effects on a patient's health, with metabolic acidosis being characterized by lower-than-normal amounts of bicarbonate in the blood and potentially altered pCO2 if the body has compensated.