If there is a metabolic acidosis, the bicarbonate (HCO₃^–) and base excess (BE) will abnormally reduced; remember too much carbon dioxide, or not enough bicarbonate will cause an acidosis.

Diagram: Uncompensated Metabolic Acidosis

If there is a metabolic abnormality causing an abnormal pH, the respiratory system will work to compensate by increasing or decreasing the CO₂ in the system. Carbon dioxide is an acidic compound, so pH can be controlled by increasing or decreasing the amount of acid in the system. In metabolic acidosis, the respiratory system will increase ventilation to remove carbon dioxide from the system. The result is a return to normal pH, as seen below.

Diagram: Metabolic Acidosis with Complete Respiratory Compensation

The example we used was Diabetic Ketoacidosis. One of the presenting features of diabetic ketoacidosis is Kussmaul breathing; the deep, rapid breathing, described as a gasping. This is respiratory compensation for a metabolic acidosis.