[Respiratory complications of massive obesity].

Massive obesity may lead to serious, and sometimes fatal, respiratory complications. Alterations of ventilatory mechanics and function are well known; they include a decrease in respiratory compliance, an increase in ventilatory work and a restrictive pulmonary disease. Hypoxemia is rather due to an impaired ventilation/perfusion ratio than to alveolar hypoventilation. Sleep Apnea Syndrome (SAS) is very frequent in excessively obese patients. These subjects with daytime hypersomnolence should be systematically screened for SAS before the occurrence of life-threatening complications. Continuous positive airway pressure ventilation through a nasal mask is the treatment of choice of SAS especially since the results of body weight reduction and ENT surgery are inconstant and variable in these patients.