Common Acid-Base Disturbance Classifications
Respiratory Acid-Base Disturbances
Primary respiratory disturbances
As PaCO2 is controlled by the lung, changes in pH caused by PaCO2 are considered respiratory disturbances
Hyperventilation lowers PaCO2, which raises pH, so is referred to as respiratory alkalosis.
Hypoventilation raises PaCO2 which decreases the pH, so is called respiratory acidosis.
Disorders are identified as
Acute ventilatory failure (respiratory acidosis)
Acute ventilatory failure with partial renal compensation
Chronic ventilatory failure with complete renal compensation
Acute alveolar hyperventilation (respiratory alkalosis)
Acute alveolar hyperventilation with partial renal compensation
Chronic alveolar hyperventilation with complete renal compensation
Metabolic Acid-Base Disturbances
Primary metabolic disturbances
These disturbances involve a gain or loss of fixed acids or HCO3–.
Both will appear as changes in HCO3– as changes in fixed acids will alter the amount of HCO3– used in buffering.
A decrease in HCO3– results in a metabolic acidosis.
An increase in HCO3- results in metabolic alkalosis.
Disorders are identified as:
Metabolic acidosis with partial respiratory compensation
Metabolic acidosis with complete respiratory compensation
Metabolic alkalosis with partial respiratory compensation
Metabolic alkalosis with complete respiratory compensation
Both metabolic and respiratory acidosis
Both metabolic and respiratory alkalosis