Fig. 4.

Main pathophysiological mechanisms involved in the occurrence of weaning-induced pulmonary oedema. The decrease is intrathoracic pressure is mediated through the contraction of the diaphragm and extradiaphragmatic respiratory muscles. It may lead to an increase in systemic venous return and cardiac preload. The decrease in intrathoracic pressure is also responsible for an increase in left ventricular afterload. The increase in right ventricular preload could induce a right ventricular dilation that can lead to ventricles interdependence and impaired left ventricular compliance potentially exacerbated by myocardial ischaemia