Abstract
A rising prevalence of obesity is reported over time and throughout the world. At
the same time, the acute respiratory distress syndrome (ARDS) remains an important
public health problem, accounting for approximately 10% of intensive care unit admissions
and leading to significant hospital mortality. Even in the absence of acute illnesses,
obesity affects respiratory mechanics and gas exchange in the setting of a restrictive
disease. In the presence of ARDS, obesity adds various challenges to a safe and effective
management of respiratory support. Difficult airway management, altered lung and chest
wall physiology, and positional gas trapping are routinely encountered. The management
of such difficult cases is generally empiric, as it is based on small-sized, physiologic
studies or on suggestions from the general anesthesia literature. The present review
focuses on those cases in which ARDS is coincident with obesity, with the aim of presenting
treatment options based on the current evidence. The first part summarizes the epidemiology
of obesity and ARDS. Then the diagnostic challenges due to obesity-related artifacts
of the different imaging techniques will be presented. A subsequent, detailed description
of the altered respiratory anatomy and physiology of obesity will provide help in
selecting an optimal, individually tailored strategy of support. Furthermore, we will
discuss how esophageal manometry should be used to adjust the settings of positive
end-expiratory pressure and tidal volume; the challenges of prone positioning and
extracorporeal support; and the optimal strategies for weaning from mechanical ventilation,
including when and how to perform a tracheostomy.
Keywords
ARDS - obesity - mechanical ventilation
