Total Respiratory System, Lung and Chest Wall Mechanics, Lung Volumes and Gas-Exchange in Morbidly Obese Patients During General Anesthesia

Morbidly obese patients present an increased risk of developing anesthetic problems during surgery (1,2). Among them, respiratory comphcations should be carefully considered since these patients are particularly prone to developing severe hypoxemia, even in the absence of previously demonstrable intrinsic pulmonary disease (3). Respiratory comphcations may be caused not only by the surgical procedure itself, but also by the severe respiratory mechanical changes occurring during anesthesia and paralysis. Although the mechanical properties of the total respiratory system, the lung and the chest wall have been extensively investigated in spontaneously breathing patients (4-8), little attention has been given to the modifications occurring during anesthesia and paralysis.