Background: Morbid obesity profoundly alters respiratory mechanics by elevating pleural and chest wall pressure, rendering standard airway-pressure-based ventilation unreliable in patients with acute respiratory distress syndrome (ARDS). Esophageal balloon catheter enables estimation of pleural pressure and calculation of transpulmonary pressure, allowing individualized PEEP titration beyond what airway pressure alone can provide.

Case Summary: A 50-year-old morbidly obese woman (BMI 43.15 kg/m²) developed severe ARDS (PaO₂/FiO₂ ratio ~84) following laparoscopic revisional bariatric surgery. Despite pressure-regulated volume control with a set tidal volume of 500 mL, only 132 mL was delivered, indicating markedly compromised respiratory compliance unexplained by airway pressure alone. An esophageal balloon catheter was inserted and used to guide PEEP titration based on transpulmonary pressure. PEEP was escalated to 25 cmH₂O guided by esophageal balloon catheter and subsequently weaned in a stepwise manner over Four days. The patient was successfully extubated on day four of ICU admission, with marked improvement in arterial blood gas parameters.

Conclusion: This case highlights the critical role of esophageal balloon catheter guided ventilation in obese ARDS patients where airway pressure is a misleading surrogate for lung mechanics. Transpulmonary pressure-guided PEEP titration enabled safe use of high PEEP levels that facilitated alveolar recruitment and ultimately successful extubation.