In this line, cyclic collapse/reopening has also been recognized as a determinant of VILI [43].Cardiac output, stroke volume, and ejection fraction selleck chem Enzalutamide were increased during hypervolemia. Increased pulmonary perfusion may also directly damage the lungs. In a model of VILI, Lopez-Aguilar and colleagues [44] have shown that the intensity of pulmonary perfusion contributes to the formation of pulmonary edema, adverse distribution of ventilation, and histological damage.In hypervolemia, we observed an increase in IL-6 mRNA expression in lung tissue, but PCIII mRNA expression did not change, which may be explained by the absence of hyperinflation [12]. Additionally, VCAM-1 and ICAM-1 mRNA expressions were elevated in HYPER group suggesting endothelial activation due to vascular mechanical stretch.

Despite increased lung injury and activation of the inflammatory process, hypervolemia was not associated with increased distal organ injury. Furthermore, hypovolemia and normovolemia did not contribute to distal organ injury, but rather protected the lungs from further damage. Our observation supports the claim that the lungs are particularly sensitive to fluid overload [45]. Lung-borne inflammatory mediators can spill over into the circulation and promote distal organ injury. However, when protective mechanical ventilation is used, decompartmentalization of the inflammatory process is limited [46].Interactions between recruitment maneuvers and volemiaThe low VT and airway pressure concept has been shown to decrease the mortality in ALI/ARDS patients [1].

Given the uncertain benefit of RMs on clinical outcomes, the routine use of RMs in ALI/ARDS patients cannot be recommended at this time. However, RMs have been shown to improve oxygenation without serious adverse events [11]. Furthermore, other papers suggested that RMs may be useful before PEEP setting, after inadvertent disconnection of the patient from the mechanical ventilator or airways aspiration [47]. Finally, RMs have been proposed to further improve respiratory function in ALI/ARDS patients in prone position [48]. Thus, in our opinion, their judicious use in the clinical setting may be justified.In our animals, RMs reduced alveolar collapse and increased normal aerated tissue independent of the degree of volemia. Along this line, experimental and clinical studies have shown that improvement in lung aeration is associated with better lung mechanics [49-51].

RMs improved oxygenation during hypervolemia, probably because of the higher amount of collapsed lung tissue, which may increase the effectiveness of RMs reversing atelectasis and decreasing Brefeldin_A intrapulmonary shunt. Gattinoni and colleagues [51] have shown that the beneficial effects of RMs are more pronounced in patients with higher lung weight and atelectasis.