[Pumpless extracorporeal lung assist using arterio-venous shunt in severe ARDS. Experience with 30 cases]

Extracorporeal lung assist has been proposed as an invasive measure in patients with acute respiratory distress syndrome (ARDS) when oxygenation is critically impaired. However, this technique generally requires high personnel and technical resources. We report on a new system, which is characterised by a short circuit arterio-venous shunt using arterio-venous pressure gradient as driving force (pumpless extracorporeal lung assist [pECLA]).

In 30 patients with ARDS due to multitrauma, pneumonia or after surgery (p(a)O(2)/F(I)O(2)-ratio 67+/-23 mmHg) pECLA was established by insertion of cannulae to the femoral artery and vein followed by connection with a membrane gas exchanger. For this system, only "low dose" continuous heparin infusion is required.

Arterial oxygenation was acutely and significantly increased by pECLA (p(a)O(2)/F(I)O(2)=103+/-56 mmHg 2 h after begin) and carbon dioxide removal was markedly enhanced in 25 out of 30 patients (87%) allowing a lung protective ventilation strategy. The mean duration of pECLA therapy was 6.5 days, 15 patients (50%) died due to ARDS or non-ARDS related reasons.

pECLA represents a feasable and effective treatment in patients with severe ARDS. Compared with pump-driven systems pECLA is characterised by low costs and reduced personnel requirements. However, mortality remains high in patients suffering from severe ARDS despite newer treatment modalities.