The physician orders the following mechanical ventilation settings for a patient. The patient's spontaneous respiratory rate is 22 breaths/min. What arterial blood gas abnormality may occur if the patient continues to be tachypneic at these ventilator settings? Settings: Tidal volume: 800 mL FIO2: 50 Respiratory rate: 14 breaths/min Mode assist/control PEEP: 10 cm