Certified Respiratory Therapist Practice Exam

In a patient with status asthmaticus, which metabolic state is most likely to be present?

1. Metabolic acidosis

2. Respiratory alkalosis

3. Metabolic alkalosis

4. Respiratory acidosis

The correct answer is: Respiratory alkalosis

In patients with status asthmaticus, a severe and prolonged asthma attack, the most likely metabolic state present is respiratory acidosis. This condition arises primarily because of the inability to effectively exhale carbon dioxide due to bronchoconstriction and airflow limitation. As a result, carbon dioxide accumulates in the bloodstream, leading to respiratory acidosis characterized by a decrease in blood pH. Under normal circumstances, during an asthma attack, patients might experience hyperventilation initially, which can lead to respiratory alkalosis. However, as the asthma episode worsens and the patient fatigues, the ability to hyperventilate decreases, causing a shift towards respiratory acidosis. The accumulation of carbon dioxide due to hypoventilation underscores the severity of the condition and the patient's compromised airway function. In summary, the presence of respiratory acidosis reflects the underlying pathophysiology of status asthmaticus, where the retention of carbon dioxide occurs due to ineffective ventilation, leading to acidemia.