Physiological Study of Minimally Invasive ECCO2R in Exacerbations of COPD Requiring Invasive Mechanical Ventilation

Chronic obstructive pulmonary disease (COPD) is currently the fourth leading cause of death in the U.S. and is expected to become the third leading cause of death in 2020. Morbidity and mortality in COPD result largely of acute exacerbations, which are responsible for 1.5 million ED visits and 750,000 hospitalizations per year in the U.S. The optimization of the respiratory management of acute exacerbations represents a fundamental challenge for improving prognosis and reducing mortality. The value of non-invasive ventilation (NIV) for severe acute exacerbations of COPD was formally demonstrated by randomized clinical trials. In the setting of severe COPD exacerbations, NIV is actually very largely employed, largely ahead from invasive mechanical ventilation. While the hospital mortality of patients treated with NIV has decreased over years, and is currently less than 10 %, mortality in patients treated with invasive ventilation remains as high than 25%. Mortality in patients treated with invasive ventilation after failure of NIV seems to be growing and is actually close to 30%. To improve the prognosis of patients with acute exacerbation of COPD requiring invasive mechanical ventilation is therefore a major challenge in terms of morbidity and mortality. Among the means available to achieve this goal, minimally invasive extracorporeal CO2 removal (ECCO2R) seems to be a very promising approach.

The investigators hypothesize that the addition of minimally invasive ECCO2R is likely to limit dynamic hyperinflation in COPD patients requiring invasive ventilation for an acute exacerbation, while improving gas exchange. If confirmed, it could imply a more rapid weaning from invasive ventilation in relation to:

• less hemodynamic consequences of positive pressure ventilation
• reduced risk of baro-volo trauma of the lung parenchyma
• reduction in the use of sedative drugs
• a chest configuration minimizing diaphragmatic flattening, therefore favoring the generation of higher trans-diaphragmatic pressures
• a decrease in the work of breathing (WOB), in connection with the previous point and with a decrease in alveolar ventilation required for pulmonary CO2 elimination during the ECCO2R treatment All of these elements are clinically relevant, as a reduction in the duration of invasive ventilation is associated in the literature with a decrease in the incidence of pneumonia associated with mechanical ventilation, as well as with a decrease in the duration of ICU-stay.

Inclusion criteria

• clinical exacerbation of a known or suspected COPD
• intubation and invasive mechanical ventilation since less than 72 hrs.
• ACV or CV mode (VT 8 ml/kg, RR 12/min., PEEP : 0 cmH20)
• pH < 7.30 and PaCO2 > 55 mm Hg and PEEPi (end-expiratory occlusion) > 5 cmH20
• written inform consent (patient, patient's legal surrogate)
• affiliation to a social security regime

Exclusion criteria

• Body Mass Index (BMI) > 35 kg/m2
• PaO2/FiO2 < 200 mm Hg
• history of hemorrhagic stroke
• heparin-induced thrombocytopenia
• Severe thrombopenia type II history