Respiratory Alkalosis By James L Lewis III, MD, Brookwood Baptist Health and Saint Vincent's Ascension Health, Birmingham Reviewed / Revised Jul 2021 | Modified Sep 2022 View Patient Education Etiology Pathophysiology Symptoms and Signs Diagnosis Treatment Key Points Topic Resources Arterial Blood Gas Interpretation... A-a Gradient Overview of Respiratory Alkalosis Respiratory alkalosis is a primary decrease in carbon dioxide partial pressure (P co 2) with or without compensatory decrease in bicarbonate (HCO 3 −); pH may be high or near normal.