Obesity and ARDS

Abstract

Obesity prevalence continues to increase globally, with figures exceeding 30% of some populations. Patients who are obese experience alterations in baseline pulmonary mechanics, including airflow obstruction, decreased lung volumes, and impaired gas exchange. These physiologic changes have implications in many diseases, including ARDS. The unique physiology of patients who are obese affects the presentation and pathophysiology of ARDS, and patients who are obese who have respiratory failure present specific management challenges. Although more study is forthcoming, ventilator strategies that focus on transpulmonary pressure as a measure of lung stress show promise in pilot studies. Given the increasing prevalence of obesity and the variable effects of obesity on respiratory mechanics and ARDS pathophysiology, we recommend an individualized approach to the management of the obese patient with ARDS.

Figures

Figure 1.

Components of lung volume. Patients who are obese have reduced lung volume components (TV, ERV, and RV), which results in lower VC, FRC, and TLC. ERV=expiratory reserve volume; FRC=functional reserve capacity; IRV=inspiratory reserve volume; RV=residual volume; TLC=total lung capacity; TV=tidal volume; VC=vital capacity.