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

Correlation of Acid base balance and electrolytes

We have previously discussed classification of acid base disturbances by using the results from the pH and blood gas analysis. Other laboratory data, including electrolyte results may be helpful in assessing acid base disturbances. Let's examine the correlation of arterial blood gas results with other laboratory data and clinical conditions.

Respiratory Acidosis Versus Respiratory Alkalosis

↓ pH ↑ pCO2 ↑ HCO3- ↓ Cl

Respiratory acidosis,
partially compensated

↑ pH ↓ pCO2 ↓ HCO3- ↑ Cl Respiratory alkalosis,
partially compensated

Plasma Cl levels change as part of compensation. Chloride and bicarbonate levels are inversely related during the compensation of respiratory acid base disturbances. In respiratory acidosis, as bicarbonate levels increase in the plasma, the chloride levels shift intracellularly in order to maintain electrical neutrality and help to restore a neutral pH. This is sometimes called the chloride shift and functions with the total buffering systems.

Photograph provided with permission by Radiometer America, Inc.