In COPD patients receiving supplemental oxygen, what complication requires close monitoring?

• A. Hypoglycemia.
• B. CO2 retention.
• C. Hematuria.
• D. Hypertension.

Answer: (B)

Oxygen therapy in COPD can worsen carbon dioxide retention, so close monitoring for hypercapnia is essential. In COPD, chronic CO2 retention happens because of impaired ventilation and V/Q mismatch; providing supplemental oxygen can blunt the hypoxic drive to breathe and, in some patients, worsen ventilation-perfusion imbalance, leading to rising CO2 and possible respiratory acidosis. Use pulse oximetry and arterial blood gases as needed, aiming for oxygen saturations around 88-92% to balance hypoxia risk and CO2 retention. Be alert for signs such as increasing confusion, morning headaches, or drowsiness, and adjust the oxygen dose or consider noninvasive ventilation if hypercapnia develops. Hypoglycemia, hematuria, and hypertension are not typical complications tied to oxygen therapy in COPD.