Outcomes of critically ill patients with obesity hypoventilation syndrome presenting with acute hypercapnic respiratory failure.

BACKGROUND

Acute-on-chronic hypercapnic respiratory failure (AHRF) is among the most common causes of hospitalization in patients with obesity hypoventilation syndrome (OHS), and is associated with high mortality rates

OBJECTIVES

To characterize the clinical features and identify mortality risk factors in patients with confirmed or suspected OHS admitted to the ICU for AHRF.

METHODS

Retrospective analysis of patients admitted to the respiratory-ICU of a tertiary academic hospital. Data was extracted from a prospective database covering from January 2010 to June 2025. Bivariate analyses and multivariable logistic regression were used to identify factors independently associated with in-hospital mortality.

RESULTS

Among 5025 ICU admissions, 333 patients met inclusion criteria: 266 (79.8 %) with confirmed OHS and 67 (20.2 %) classified as suspected OHS. The mean age was 50.6±14.0 years; 56.5 % were male. Overall mortality was 48 % (n=160). Noninvasive mechanical ventilation prevented intubation in 44 % of subjects. In bivariate analysis, age, Sequential Organ Failure Assessment (SOFA), Simplified Acute Physiology Score-3 (SAPS-3), and hypertension were associated with increased mortality. Multivariable regression identified age (OR 1.02 per year; p=0.039) and SOFA (OR 1.69 per point; p<0.001) as independent predictors of mortality. Conversely, tracheostomy was associated with a lower risk of death (OR 0.26; p=0.007).

CONCLUSIONS

OHS-related AHRF is a common cause of ICU admission in obese patients and is associated with high mortality. Age and SOFA score are independent predictors of poor outcomes, while tracheostomy appears to confer a survival benefit. These findings highlight the need for early identification and tailored management in this understudied population.