High-frequency oscillation combined with arteriovenous extracorporeal lung assist reduces lung injury

In order to optimize the lung-protective potential of high-frequency oscillatory ventilation (HFOV), it is currently recommended to maximize oscillatory frequencies. However, very high frequencies may lead to insufficient CO(2) elimination with severe respiratory acidosis. Arteriovenous extracorporeal lung assist (av-ECLA) allows near total CO(2) removal, thereby allowing for maximization of the lung-protective potential of HFOV. The aim of this study was to determine the impact of HFOV and av-ECLA on lung inflammation and function compared to conventional lung-protective ventilation. In a porcine surfactant depletion model of lung injury, the authors randomly assigned 16 female pigs to conventional lung-protective ventilation and HFOV/ECLA. Both strategies were combined with an "open-lung" approach. Gas exchange and hemodynamic parameters were measured at intervals during the 24-hour study period. Postmortem, lung tissue was analyzed to determine histological damage and lung inflammation. The authors found that the combination of HFOV and av-ECLA (1) allows significant reductions in mean and peak airway pressures; and (2) reduces histological signs of lung inflammation in the basal regions of the lung. HFOV/av-ECLA reduces histological signs of lung inflammation compared to conventional lung-protective ventilation strategies. Thus, combination of HFOV and av-ECLA might be a further lung-protective tool if conventional ventilation strategies are failing.