A 25-year-old patient with generalized anxiety disorder presents to the ED with shortness of breath, dizziness, and tingling in the fingers. The nurse reviews the ABG results: pH: 7.50, PaCO2: 30 mmHg HCO3: 24 mEq/L. What is the most likely acid-base imbalance?

A. Respiratory acidosis would present with a low pH (acidotic) and a high PaCO2, which is not the case here. B. Metabolic alkalosis would be suggested by an elevated pH and elevated HCO3, but here, the bicarbonate level is normal (24 mEq/L). C. Respiratory alkalosis is indicated by a pH of 7.50 (alkalosis) and a PaCO2 of 30 mmHg, which is lower than the normal range (35-45 mmHg). This low PaCO2 suggests that the patient is hyperventilating, likely due to anxiety, which causes the body to excrete too much CO2. D. Metabolic acidosis would present with a low pH and a low bicarbonate level, neither of which are seen in this case.