[Current techniques for extracorporeal decarboxylation]

The widespread use of extracorporeal lung assist (ECLA) in recent years has led to the introduction of different decarboxylation systems into clinical practice. Due to the large CO₂ transport capacity of the blood such systems require considerably lower extracorporeal blood flows and therefore allow for effective decarboxylation with reduced invasiveness and complexity. While systems derived from classical lung assist are mainly used to control severe acute hypercapnic respiratory failure, recently a growing number of therapies based on renal replacement platforms have become available ("respiratory dialysis"). Such low-flow systems still allow for effective partial CO₂ elimination and can control respiratory acidosis as well as facilitate or even enable protective and ultraprotective ventilation strategies in acute lung failure (ARDS). While the use of extracorporeal CO₂ elimination (ECCO₂R) has been shown to decrease ventilator-induced lung injury (VILI), positive effects on hard clinical endpoints such as mortality or duration of mechanical ventilation are still unproven. In light of limited evidence, ECCO₂R must be regarded as an experimental procedure. Its use should therefore at present be restricted to centers with appropriate experience.