Four hours after mechanical ventilation is initiated for a patient with chronic obstructive pulmonary disease (COPD), the patients arterial blood gas (ABG) results include a pH of 7.50, PaO2 of 80 mm Hg, PaCO2 of 29 mm Hg, and HCO3 of 23 mEq/L (23 mmol/L). The nurse will anticipate the need to
a. increase the FIO2.
b. decrease the respiratory rate.
c. increase the tidal volume (VT).
d. leave the ventilator at the current settings.
