Sevoflurane in Chronic Obstructive Pulmonary Disease Exacerbation

Prospective, open-label, single-center, study to investigate the effect of sevoflurane sedation compared to a propofol-controlled arm during COPD exacerbation requiring invasive mechanical ventilation in ICU. Primary outcome measure: Evolution of airway resistance before and after sevoflurane in COPD patients, Secondary outcomes measures: Respiratory mechanics (Maximum pressure, PEEPi and PEEPtot, trapped volume), Gas exchange by the help of blood gases, The heterogeneity of alveolar ventilation by electro-impedancemetry, Evolution of pulmonary inflammation, Trophicity and contractility of the diaphragm,