Metabolic alkalosis commonly results from which conditions, with hypokalemia often present?

• A. Metabolic Acidosis
• B. Respiratory Acidosis
• C. Metabolic Alkalosis
• D. Respiratory Alkalosis

Answer: (C)

Metabolic alkalosis is caused by a net gain of bicarbonate or a loss of hydrogen ions, which raises the blood pH. In practice, you see this most often with loss of gastric acid from prolonged vomiting or NG suction, and with diuretic use or mineralocorticoid excess that promotes renal loss of hydrogen (and often potassium). As the body becomes volume-depleted or chloride-depleted, bicarbonate is retained, further elevating its level. Hypokalemia fits here because these same states tend to cause potassium loss in the kidneys or a shift of potassium out of cells, and this potassium imbalance commonly accompanies the alkalosis. The body does attempt some compensation (slower breathing to retain CO2), but this has limited effect. Other acid-base disorders involve different primary disturbances (acid gain or CO2 changes) and would not present with the same pattern of bicarbonate elevation and often hypokalemia.