A patient diagnosed with chronic obstructive pulmonary disease (COPD) is on oxygen therapy at 3 L per nasal cannula.Which assessment finding should alert the nurse to a potential problem with this patient?

A) Respiratory rate of 26
B) Low carbon dioxide levels
C) Arterial oxygen saturation level of 99%
D) Lower oxygen saturation levels at night than during the day

In the patient with COPD,high levels of oxygen can extinguish the stimulus to breathe.In the individual with healthy lungs,the chemoreceptors are sensitive to small changes in carbon dioxide levels and effectively regulate ventilation.In patients with COPD who retain carbon dioxide,the chemoreceptors are not sensitive to small changes in carbon dioxide and regulate ventilation poorly.In these patients,it is the change in the oxygen level that stimulates changes in ventilation.Patients with COPD are at risk of retaining carbon dioxide and developing carbon dioxide narcosis induced by administration of high levels of oxygen.Uncontrolled oxygen administration may cause acute hypoventilation and carbon dioxide retention with dire consequences.Arterial oxygen saturation levels should be at 88% to 92% and no higher.Some patients with COPD have normal oxygen levels during the day but oxygen desaturation during sleep.