Which ABG pattern is expected in metabolic alkalosis?

Which ABG pattern is expected in metabolic alkalosis?

• A. High pH and low HCO3
• B. Low pH and low HCO3
• C. Low pH and high HCO3
• D. High pH and high HCO3

Answer: (D)

Metabolic alkalosis is defined by an excess of base or a loss of hydrogen ions, causing the pH to rise and the bicarbonate (HCO3−) level to increase. In arterial blood gas terms, you would see an elevated pH (alkalemia) with an elevated HCO3−. The body attempts to compensate with hypoventilation to retain CO2 and raise PaCO2, which can help move the pH back toward normal, but the primary pattern remains high pH with high bicarbonate. Therefore, the ABG pattern that fits metabolic alkalosis is high pH and high HCO3−.

Metabolic alkalosis is defined by an excess of base or a loss of hydrogen ions, causing the pH to rise and the bicarbonate (HCO3−) level to increase. In arterial blood gas terms, you would see an elevated pH (alkalemia) with an elevated HCO3−. The body attempts to compensate with hypoventilation to retain CO2 and raise PaCO2, which can help move the pH back toward normal, but the primary pattern remains high pH with high bicarbonate. Therefore, the ABG pattern that fits metabolic alkalosis is high pH and high HCO3−.