As status asthmaticus worsens, which acid-base imbalance is most likely to develop?

• A. Respiratory acidosis
• B. Respiratory alkalosis
• C. Metabolic alkalosis
• D. Metabolic acidosis

Answer: (A)

Verified step by step guidance

1. Understand the condition: Status asthmaticus is a severe, prolonged asthma attack that leads to difficulty in breathing and impaired gas exchange. This condition can cause changes in blood pH due to altered levels of carbon dioxide (CO₂).
2. Review the role of CO₂ in acid-base balance: CO₂ is a byproduct of cellular respiration and is transported in the blood. When CO₂ levels increase, it combines with water (H₂O) to form carbonic acid (H₂CO₃), which dissociates into hydrogen ions (H⁺) and bicarbonate ions (HCO₃⁻). This process lowers blood pH, leading to acidosis.
3. Analyze the progression of status asthmaticus: As the condition worsens, airway obstruction becomes more severe, leading to hypoventilation (reduced breathing). Hypoventilation causes CO₂ to accumulate in the blood, increasing the risk of respiratory acidosis.
4. Differentiate between the options: Respiratory acidosis is caused by CO₂ retention due to hypoventilation. Respiratory alkalosis occurs with hyperventilation (excessive breathing). Metabolic alkalosis and metabolic acidosis are related to changes in bicarbonate levels or other metabolic factors, not directly linked to CO₂ retention in this scenario.
5. Conclude the most likely imbalance: Based on the pathophysiology of status asthmaticus and the role of CO₂ in acid-base balance, respiratory acidosis is the most likely acid-base imbalance to develop as the condition worsens.