Quantification of Recirculation During Veno-Venous Extracorporeal Membrane Oxygenation: In Vitro Evaluation of a Thermodilution Technique.

Veno-venous extracorporeal membrane oxygenation (vv-ECMO) represents one of the most advanced respiratory support for patients suffering from severe acute respiratory distress syndrome. During vv-ECMO a certain amount of extracorporeal oxygenated blood can flow back from the reinfusion into the drainage cannula without delivering oxygen to the patient. Detection and quantification of this dynamic phenomenon, defined recirculation, are critical to optimize the ECMO efficiency.

Positive End-expiratory Pressure and Mechanical Power.

Background: Positive end-expiratory pressure is usually considered protective against ventilation-induced lung injury by reducing atelectrauma and improving lung homogeneity. However, positive end-expiratory pressure, together with tidal volume, gas flow, and respiratory rate, contributes to the mechanical power required to ventilate the lung. This study aimed at investigating the effects of increasing mechanical power by selectively modifying its positive end-expiratory pressure component.

Extracorporeal CO2 Removal: The Minimally Invasive Approach, Theory, and Practice.

Objectives: Minimally invasive extracorporeal CO2 removal is an accepted supportive treatment in chronic obstructive pulmonary disease patients. Conversely, the potential of such technique in treating acute respiratory distress syndrome patients remains to be investigated. The aim of this study was: 1) to quantify membrane lung CO2 removal (VCO2ML) under different conditions and 2) to quantify the natural lung CO2 removal (VCO2NL) and to what extent mechanical ventilation can be reduced while maintaining total expired CO2 (VCO2tot = VCO2ML + VCO2NL) and arterial PCO2 constant.

Extracorporeal Gas Exchange.

Extracorporeal gas exchange is increasingly used for various indications. Among these are refractory acute respiratory failure, including the acute respiratory distress syndrome (ARDS), and the avoidance of ventilator-induced lung injury (VILI) by enabling lung-protective ventilation. Additionally, extracorporeal gas exchange allows the treatment of hypercapnic respiratory failure while helping to unload the respiratory muscles and avoid intubation and invasive ventilation, as well as facilitating weaning from the ventilator.

Determinants and Prevention of Ventilator-Induced Lung Injury.

Ventilator-induced lung injury develops from interactions between the lung parenchyma and applied mechanical power. In acute respiratory distress syndrome, the lung is smaller size with an inhomogeneous structure. The same mechanical force applied on a reduced parenchyma would produce volutrauma; the concentration of mechanical forces at inhomogeneous interfaces produces atelectrauma.