Acid Base Balance / Blood Gas Testing - Lesson 1
Chemistry Course Overview

Correlation of Acid base balance and anion gap

Metabolic acidosis is typically classified into two categories based on anion gap levels. When anion gap is increased with metabolic acidosis the plasma chloride levels are usually normal but plasma potassium is increased. The change in anion gap from normal should equal the change in HCO3- in simple acid base disturbances.

Metabolic Acidosis With Increased Anion Gap, partially compensated

↓ pH ↓ HCO3- ↓ pCO2 ↑ K, norm. Cl ↑ Anion gap

Common causes of metabolic acidosis with increased anion gap

renal failure ↓ output and ↑ serum creatinine
ingestion of volatile organic toxins ↑ osmolal gap
production of acids ↑ lactic acid or ↑ ketones