The characteristic abnormality of the lung in MODS is a failure of normal gas exchange, reflected predominantly in arterial hypoxemia. Multiple pathologic factors contribute to impaired gas exchange. Early in the course of lung injury, atelectasis and intravascular thrombosis or altered regional flow contribute to ventilation/perfusion mismatch, while increased capillary permeability leads to alveolar flooding and an increased diffusion distance for oxygen. Regional injury resulting from infection or trauma contributes to compromised lung function. With the institution of ventilatory support, lung injury can be aggravated through what has been termed volutrauma and barotrauma, leading to further atelectasis in dependent lung zones, and cyst formation in the anti-dependent zones. Finally, the process of tissue repair, initiated with the influx of inflammatory cells into the injured lung, results in fibrosis and hyaline membrane formation, the cardinal pathologic features of late ARDS.
The characteristic abnormality of the lung in MODS is a failure of normal gas exchange, reflected predominantly in arterial hypoxemia. Multiple pathologic factors contribute to impaired gas exchange. Early in the course of lung injury, atelectasis and intravascular thrombosis or altered regional flow contribute to ventilation/perfusion mismatch, while increased capillary permeability leads to alveolar flooding and an increased diffusion distance for oxygen. Regional injury resulting from infection or trauma contributes to compromised lung function. With the institution of ventilatory support, lung injury can be aggravated through what has been termed volutrauma and barotrauma, leading to further atelectasis in dependent lung zones, and cyst formation in the anti-dependent zones. Finally, the process of tissue repair, initiated with the influx of inflammatory cells into the injured lung, results in fibrosis and hyaline membrane formation, the cardinal pathologic features of late ARDS.
การแปล กรุณารอสักครู่..
