Acute Respiratory Distress Syndrome (ARDS) and Acute Lung Injury (ALI) belong to the most frequent indications for admission to an intensive care unit. Both ARDS and ALI are mainly characterized by a ventilation-perfusion mismatch resulting in intrapulmonary shunting and hence in hypoxemia and hypercapnia. Improved understanding of the pathogenesis has led to advances in the treatment of ARDS/ALI. However, standard supportive care including a protective ventilatory strategy with low tidal volumes is frequently not successful in improving gas exchange in severe cases of ARDS/ALI. Therefore, veno-venous extracorporeal membrane oxygenation (ECMO) may be a life-saving therapy ensuring a sufficient gas exchange. However, the clinical use of ECMO is limited due to the size of traditionally used centrifugal pumps and associated risks of adverse events. In contrast, the DeltaStream-system represents a miniaturized extracorporal circuit consisting of a diagonal blood pump and characterized by a significantly reduced foreign surface area and a decreased extracorporeal volume. We thus hypothesized that the DeltaStream-system may reduce contact activation of the blood resulting in less blood trauma. In addition, the aim of the present study was to test safety and efficacy of the DeltaStream-system for extracorporeal lung assist in pigs with experimental induced ALI. After the induction of experimental ALI in 6 pigs by repetitive lung lavages, veno-venous ECMO was started and performed for 6 hours. Extracorporeal blood flow was set to equal 30% of cardiac output, and gas flow with a FiO2 of 1,0 was set to equal blood flow. Maintaining an ACT (Activated Clotting Time) of 123±23 s, no circulatory impairment or thrombus formation was revealed during ECMO. Furthermore, neither free plasma Hb nor fibrinogen concentrations increased significantly during ECMO. Pigs showed no cardiocirculatory dysfunction during the observation period. Gas transfer across the extracorporeal oxygenators allowed an efficacious CO2 removal in all animals. However, only in 2 animals a marked increase in PaO2 was notable. In conclusion, the use of the DeltaStream-system in our study was not associated with major blood damage, thrombus formation or hemodynamic impairment. Thus, the DeltaStream-system may be a promising new tool in the treatment of ARDS/ALI by ECMO
