The fоllоwing dаtа hаve been cоllected from a 70 kg (154 lb) patient receiving volume-controlled ventilation. VENT SETTINGS Mode AC Vent RR 12 Vt 550 ml FI02 0.8 PEEP 10 cm H20 ABG RESULTS pH 7.37 PaCO2 42 torr Pa02 161 torr HCO3 25 mEq/L BE 0 Which of the following ventilator setting changes should the respiratory therapist recommend?