Metabolic Alkalosis and Respiratory Alkalosis

Occurs in:

• Diuretic therapy (low potassium) and pneumonia
• Vomiting (H^₊ loss) and congestive cardiac failure (hyperventilation)

ABG hallmark:  the pCO₂ will be reduced and the HCO₃^– raised. [11,12]

For example, in a patient who has been vomiting profusely and is, as a result, highly anxious with raised respiratory rate:

• pH   7.53
• pCO₂   2.7 kPa
• pO₂   10.9 kPa
• bicarbonate  34 mmol/L

The clinical picture needs to be considered – this patient is alkalotic with a low CO₂, indicating a respiratory component, but the bicarbonate is high, rather than normal or low. [11,12]