The role of poly (ADP-ribose) polymerase in ventilator-induced lung injury

Some issues have not been addressed appropriately. The authors show increased levels of TNFα in lung homogenate after 2 hours of lung-protective ventilation (LPV). Previous data from our laboratory have shown in the healthy mouse lung that so-called protective mechanical ventilation (tidal volume, 8 ml/kg; peak airway pressure, 10 to 12 cmH2O; positive end-expiratory pressure, 4 cmH2O) induces a pulmonary inflammatory response [2]. In addition to elevated levels of TNFα, we found increased expression of IL-1β, IL-6, and keratinocyte-derived chemokine in the lung homogenate and found an increased number of pulmonary leucocytes in mice mechanically ventilated for 2 hours. Electron microscopy revealed evidence for type I pneumocyte membrane disruption and endothelial detachment, indicating structural injury. In line with the findings by Kim and colleagues, the wet/dry ratio was not affected after 2 hours of mechanical ventilation – although in our study 4 hours of protective ventilation did increase the wet/dry ratio.