Extracorporeal CO2 Removal in Acute Exacerbation of COPD Not Responding to Non-Invasive Ventilation

The study compare 2 strategies for COPD patients not responding to non invasive ventilation: the gold standard which is mechanical ventilation and a new technique which is extracorporeal CO2 removal. This technique have been implemented in februrary 2015 in our intensive care unit so we choose to compare patients' outcome before and after the arriving of this device.