The use of mechanical ventilation in hypovolemic conditions leads to various physiologic effects. The right ventricular preload decreases due to the compression of the superior vena cava and an increase in intramural right atrial pressure, causing a decrease in transmural right atrial pressure. In West zones I and II, pulmonary capillaries are compressed, leading to an increase in right ventricular afterload. In West zone III, the increase in alveolar pressure pushes blood from the capillaries towards the left side of the heart. Additionally, there is a decrease in left ventricular afterload due to an increase in pleural pressure. The abbreviations used in the text include LA for left atrium, LV for left ventricle, Palv for alveolar pressure, Ppl for pleural pressure, RA for right atrium, and RV for right ventricle.
