The effects of hydrogen on ventilator-induced lung injury (VILI) induced by mechanical ventilation with low tidal volume (TV) (10 mL/kg). (a) Partial pressure of arterial oxygen (PaO2) levels of mice ventilated with 2% hydrogen for 5 hours were significantly higher than those of mice ventilated with 2% nitrogen. N = 6 for each group. (b) Lung edema caused by VILI was determined by measuring the wet-to-dry (W/D) ratio. Hydrogen inhalation therapy ameliorated VILI-induced lung edema caused by mechanical ventilation with low TV. N = 6 for each group. (c) Serum tumor necrosis factor-alpha (TNFα) concentrations were measured after VILI with TV of 10 mL/kg for 5 hours. Hydrogen treatment significantly reduced VILI-induced elevation of serum TNFα. N = 6. *P < 0.05 versus sham/N2 and sham/H2; #P < 0.05 versus VILI/N2.