Acid-Base Physiology

5.3 Metabolic Acidosis : Maintenance

The disorder is maintained as long as the primary cause persists.

Additionally, in many cases the acid-base disturbance tends to increase in severity while the problem causing it persists though this is not absolute.

For example with diabetic ketoacidosis, the pH will remain low as long as the problem (relative or absolute insulin deficiency) persists and the levels of plasma keto-anions continue to rise. However, these increased plasma levels of keto-anions exceed the renal threshold and are excreted in the urine. This will limit the rate of rise as long as this additional mechanism of excreting the acid anions persists. This renal excretion also means that once treatment commences, there is now a deficiency of keto-anions to be metabolised to regenerate bicarbonate and consequently there is can be a significant delay in the return of the plasma pH to normal.