The patient has severe hyperthyroidism and will have surgery tomorrow. What assessment is most important for the nurse to assess in order to detect development of the acid-base imbalance for which the patient has highest risk?

A) Urine output and color
B) Level of consciousness
C) Heart rate and blood pressure
D) Lung sounds in lung bases

Thyroid hormone increases metabolic rate, causing a patient with severe hyperthyroidism to have high risk of metabolic acidosis from increased production of metabolic acids. Metabolic acidosis decreases level of consciousness. Changes in urine output, urine color, and lung sounds are not signs of metabolic acidosis. Although metabolic acidosis often causes tachycardia, many other factors influence heart rate and blood pressure, including thyroid hormone.