Mechanical ventilation and the kidney

摘要

Mechanical ventilation increases intrathoracic pressures when compared with spontaneous breathing. During spontaneous inspiration intrapleural and intra-alveolar pressure decreases, and a pressure gradient in the airways generates inspiratory airflow. This mechanism also supports circulation: venous return is facilitated by the negative intrathoracic pressure as well as by the slightly positive intra-abdominal pressure generated by the downward diaphragm movement during spontaneous inspiration.