As we have discussed, if too much carbon dioxide was removed from the body, by taking lots of rapid, shallow breaths, the pH of the blood would begin to rise. This is respiratory alkalosis, and can be differentiated from a metabolic alkalosis by the abnormally low PaCO2.
Diagram: Uncompensated Respiratory Alkalosis
In most scenarios, respiratory alkalosis is caused by hyperventilation. Understanding the cause of hyperventilation will help in the management of these patients. Hyperventilation can caused by a number of factors, including a central process, hypoxaemic process, pulmonary process or iatrogenic process.
Causes of hyperventilation:
If this acid-base imbalance is prolonged, the metabolic system will begin compensating for an alkalotic environment by removing bicarbonate from the system. This metabolic compensation for a respiratory alkalosis normalises the pH.
Diagram: Respiratory Alkalosis with Complete Metabolic Compensation
As you can see, respiratory alkalosis may be an acute process or a chronic process, however, the metabolic compensatory process that returns the pH to normal range occurs over the course of days.