[Evaluating lung failure and the limits of artificial respiration]

The treatment and outcome of the respiratory failure decisively depend on its pathophysiological background. Besides simple blood gas analysis the investigation of the respiratory mechanics, interstitial lung water and the monitoring of the pulmonary pressure are necessary for an exact diagnosis. As a scoring method of lung failure the classification by Murray and Morell is most common. In addition to normal volume or pressure controlled artificial ventilation the treatment of lung failure sometimes requires new but accepted modes of ventilation as inversed ratio ventilation, permissive hypercapnea and high frequency ventilation. New methods as negative pressure ventilation, extracorporeal lung ventilation and liquid or partial liquid ventilation are not common yet and should be used only under special conditions. As a supplement of these modes of ventilation the application of prostacyclins, nitric oxide, surfactant and inhibitors of the arachidonic pathway is under clinical investigation. A limitation of the treatment of lung failure should be considered in irreversible multiple organ failure.