A high intrathoracic pressure may impede venous return and increase pulmonary vascular resistance. This concurrent right ventricular preload reduction and afterload increase might cause right ventricular dysfunction/failure. On the other hand, the placement of a cuff leak results in a lower (by approx. 5-6 cmH2O) mean tracheal pressure relative to the set HFO-ventilator mean airway pressure (mPaw), with consequent unloading of the right ventricle. In addition, further unloading of the right ventricle can be expected through the combined use of a cuff leak, TGI, and a high HFO bias flow; these measures improve PaCO2 control and may prevent excessive, hypercapnia-induced increases in pulmonary vascular resistance. Right ventricular function can be assessed by transesophageal echocardiography (TEE) as previously described. Right ventricular dysfunction and associated dilatation may cause cardiac output reduction and coronary hypoperfusion; the latter may further compromise right ventricular performance and contribute to right ventricular failure.