A patient with acute respiratory distress syndrome (ARDS) is being managed with the following ventilator settings: Assist-Control Ventilation Ventilator set rate = 10 breaths/minute Total respiratory rate = 24 breaths/minute Exhaled tidal volume 750 ml PEEP 5 cm H20 FIO2 100% On these setting he has the following blood gases: pH 7.35 PaCO2 35 mm Hg PaO2 65 mm Hg SaO2 92% Because of patient agitation and some breathing discoordination, it is decided to paralyze the patient. Without changing any ventilator settings, what is the most likely scenario after paralysis? a) Oxygenation and ventilation will improve b) Oxygenation will be unpreditable but ventilation will stay the same c) Oxygenation will be unpredictable but ventilation will worsen d) Oxygenation will worsen but ventilation will be unpreditable. e) Oxygenation and ventilation will worsen. The answer is ....(e) Oxygenation and ventilation will worsen. By paralyzing the patient you effectively change respiratory rate from 24 full ventilator breaths/minute to 10 full ventilator breaths/minute. Thus it would be expected that both ventilation and oxygenation will worsen, i.e., his PaCO2 will go up and PaO2 will go down.