A 69-year-old woman is taking large amounts of aspirin for osteoarthritis, and now complains of ringing in her ears and nausea.For the above patient with new symptoms, select the most likely acid base disorder.

Chronic salicylate use can cause respiratory alkalosis. Severe salicylate toxicity results in an anion gap metabolic acidosis such as during an overdose. During acute hyperventilation, plasma bicarbonate concentrations fall by approximately 3 mEq/L when the arterial pressure of CO2 falls to about 25 mm Hg. Acute respiratory alkalosis can be caused by anxiety, central nervous system (CNS) disorders, drugs, or fever. Chronic respiratory alkalosis occurs in pregnancy and liver disease as well.