Methods
ARDS
ARDS
The study was approved by the local ethics committee (Medizinische Ethikkommission II, University Medical Centre Mannheim, Medical Faculty Mannheim of the University of Heidelberg, Mannheim, registration number 2018-606N-MA) and registered at the German Clinical Trials Register (DRKS00017237). After obtaining written informed consent from the patients or next of kin, we collected prospective data from 20 patients with severe ARDS managed with V-V ECMO admitted to the Department of Anesthesiology and Critical Care Medicine, University Medical Centre Mannheim, Medical Faculty Mannheim of the University of Heidelberg in Mannheim, Germany. The attending physician initiated V-V ECMO therapy according to the standard operating procedures of the department when patients fulfilled the criteria published in the guidelines of the Extracorporeal Life Support Organization [Correct positioning of the central venous catheter was verified by chest radiography as per the standard operating procedure of our unit. During the measurement, patients were sedated with midazolam (5–15 mg/h) and sufentanil (50–250 µg/h) to achieve a Richmond Agitation-Sedation Score of − 5 [Patients were eligible for the study as soon as an ECBF of 2 l/min generated a partial pressure of oxygen of at least 60 mmHg with standardized respiratory settings (respiratory rate of 12–16/min, tidal volume of 3 ml/kg of predicted body weight, positive end-expiratory pressure according to the ARDS Network recommendations [