Apnea-hypoxia is the main breathing stimulus for a client with copd. excessive oxygen administration may lead to apnea by removing that stimulus. anginal pain results from a reduced myocardial oxygen supply. a client with copd may have anginal pain from generalized vasoconstriction secondary to hypoxia; however, administering oxygen at any concentration dilates blood vessels, easing anginal pain. respiratory alkalosis results from alveolar hyperventilation, not excessive oxygen administration. in a client with copd, high oxygen concentrations decrease the ventilatory drive, leading to respiratory acidosis, not alkalosis. high oxygen concentrations dont cause metabolic acidosis.