Obesity and Mechanical Ventilation

As the number of patients with obesity that will require mechanical ventilation is destined to increase in the next years, the development of strategies to optimize the care of these patients is mandatory. The pivotal feature of breathing physiology in obesity is high pleural pressure, resulting in atelectasis, high elastance of the lung, expiratory flow limitation, and ineffective gas exchange. In the presence of acute respiratory distress syndromes, inflammatory edema and high pleural pressure may be additive in further impairing the function of the lungs. A physiological approach based on the recruitment of collapsed alveolar units, the setting of a positive end-expiratory pressure corresponding to the lowest elastance of the respiratory system, and the targeting of an adequate transpulmonary pressure of end-exhalation could counteract the deleterious effects of an excessively high pleural pressure, ameliorating the cardiopulmonary function of patients with obesity during mechanical ventilation.