Influence of mechanical ventilation and sepsis on redox balance in diaphragm, myocardium, limb muscles, and lungs

Abstract

Mechanical ventilation (MV), using high tidal volumes (VT), causes lung (ventilator-induced lung injury [VILI]) and distant organ injury. Additionally, sepsis is characterized by increased oxidative stress. We tested whether MV is associated with enhanced oxidative stress in sepsis, the commonest underlying condition in clinical acute lung injury. Protein carbonylation and nitration, antioxidants, and inflammation (immunoblotting) were evaluated in diaphragm, gastrocnemius, soleus, myocardium, and lungs of nonseptic and septic (cecal ligation and puncture 24 hours before MV) rats undergoing MV (n = 7 per group) for 150 minutes using 3 different strategies (low VT [VT = 9 mL/kg], moderate VT [VT = 15 mL/kg], and high VT [VT = 25 mL/kg]) and in nonventilated control animals.