Mechanical ventilation for ICU patient with obesity: current best practices and future directions

Abstract

Abstract: Obesity is increasingly prevalent among critically ill patients and profoundly alters respiratory mechanics, gas exchange, and cardiopulmonary interactions, complicating ventilatory management. Excess adipose tissue increases pleural pressure, reduces functional residual capacity, and promotes airway closure and atelectasis, increasing susceptibility to hypoxemia, hypercapnia, and ventilator-induced lung injury. These physiological alterations necessitate tailored ventilatory strategies distinct from those used in patients without obesity. Lung-protective ventilation using tidal volume indexed to predicted body weight remains the cornerstone of management, as lung size does not increase proportionally with body mass. Patients with obesity often require higher positive end-expiratory pressure to counteract elevated pleural pressure and prevent airway closure although optimal titration strategies remain uncertain. Interpretation of airway pressures requires caution, as increased chest wall elastance may result in elevated plateau and driving pressures without excessive lung stress. Adjunctive monitoring tools, including esophageal pressure measurement and electrical impedance tomography, may help individualize ventilatory management by improving assessment of transpulmonary pressure and regional ventilation. Airway management is particularly challenging in patients with obesity due to rapid oxygen desaturation and increased risk of difficult intubation; positive-pressure preoxygenation and video laryngoscopy improve procedural safety. Adjunctive therapies, such as prone positioning, non-invasive ventilation, and extracorporeal membrane oxygenation, are feasible and may provide benefit when clinically indicated. Liberation from mechanical ventilation requires careful assessment, and prophylactic non-invasive ventilation may reduce extubation failure in selected patients. Despite increasing recognition of obesity-specific physiology, most current recommendations are extrapolated from general ICU populations. Dedicated clinical trials are needed to define optimal ventilatory strategies and improve outcomes in this growing population of critically ill patients with obesity.