Progressive Care Nursing Certification (PCCN) Practice Exam

What condition is primarily caused by abnormal alveolar minute ventilation?

1. Hypoxemia

2. Hypercapnia

3. Respiratory alkalosis

4. Metabolic acidosis

The correct answer is: Hypercapnia

The condition primarily caused by abnormal alveolar minute ventilation is hypercapnia. When alveolar ventilation decreases, the body is unable to effectively remove carbon dioxide (CO2) produced by metabolism. This leads to an accumulation of CO2 in the bloodstream, resulting in hypercapnia, which is characterized by elevated arterial CO2 levels. Abnormal minute ventilation may be due to various factors such as hypoventilation, which can occur in conditions like respiratory muscle weakness, sedation, or severe lung disease. When there is insufficient ventilation, the excretion of CO2 is compromised, leading to its accumulation and consequently increasing the acidity of the blood (respiratory acidosis). Hypoxemia, while it can occur concurrently with hypercapnia, is primarily related to the inability to adequately oxygenate the blood rather than the accumulation of CO2. Respiratory alkalosis is a different condition that arises from excessive ventilation, causing CO2 levels to drop rather than accumulate. Metabolic acidosis is not directly related to abnormal alveolar ventilation but involves primary disorders of acid-base balance stemming from metabolic processes.