ScholarWorks@중앙대학교

초록

Background: Obesity is widely associated with numerous chronic conditions; however, critically ill patients sometimes exhibit the so-called “obesity paradox”, showing similar or lower mortality compared to normal-weight individuals. In acute respiratory distress syndrome (ARDS), the impact of obesity on outcomes remains controversial, particularly regarding ventilator parameters such as positive end-expiratory pressure (PEEP) and driving pressure. We examined whether an obesity paradox exists in ARDS and assessed whether mechanical ventilation (MV) settings differ across body mass index (BMI) categories. Methods: In this retrospective analysis, 595 adult patients admitted from March 2018 to February 2021 were analyzed. Patients were stratified into four BMI categories (underweight <18.5 kg/m2, normal 18.5–24.9 kg/m2, overweight 25–29.9 kg/m2, and obese ≥30 kg/m2). Ventilator parameters were collected within 12 hours of initiation of MV. Hospital mortality served as the primary outcome. Results: Among the study cohort, 84 patients (14.1%) were underweighted, 371 (62.4%) had normal BMI, 109 (18.3%) were overweight, and 31 (5.2%) were obese (BMI ≥30 kg/m2). The obese group presented significantly higher median PEEP and driving pressure values than others. However, no significant differences in hospital mortality were observed across the four BMI categories (P=0.56). Notably, hospital mortality was highest in the normal BMI group, suggesting a possible inverted U-shaped pattern in which overweight/obese individuals did not show increased mortality. In multivariable analysis, obesity was not independently associated with mortality. Conclusions: There was no significant difference in hospital mortality between the high BMI group and the other groups, and the higher mortality observed in the normal BMI group may be explained by the greater proportion of solid tumors and hematologic malignancies. Our findings highlight that higher PEEP or driving pressure in obese ARDS patients does not necessarily translate to worse outcomes. More extensive studies are warranted to explore how BMI modifies ventilator strategies and clinical outcomes in ARDS.

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