Please select from below:
The abnormality chosen is:
a decreased serum bicarbonate level. This is indicative of two possible underlying acid-base abnormalities. Both metabolic acidosis and compensated respiratory alkalosis are possible causes of this abnormality. An arterial blood gas will be necessary to determine which acid-base disorder is present, and the underlying etiology will be found in the appropriate differential diagnosis. If a metabolic acidosis is present, the next step is to calculate the anion gap because the differential for a non-gap and an elevated gap acidosis are different. If respiratory alkalosis is present, the alveolar-arterial oxygen gradient (A-a gradient) should be calculated as the next step of the workup to narrow the differential diagnosis for the true underlying cause.