Impact of obstructive sleep apnea on the obesity paradox in critically ill patients

Patients admitted to an intensive care unit (ICU) frequently suffer from multiple chronic diseases, including obstructive sleep apnea (OSA). Until recently OSA was not considered as a key determinant in an ICU patient's prognosis. The objective of this study was to document the impact of OSA on the prognosis of ICU patients.

Data were retrospectively collected concerning adult patients admitted to ICU at two university hospitals. In a nested study OSA status was checked using the hospital electronic medical records to identify exposed and unexposed cases. The following outcomes were considered: length of stay in the ICU, ICU mortality, in-hospital mortality, ventilator-associated pneumonia (VAP).

Out of 5146 patients included in the study, 289 had OSA at ICU admission (5.6%). After matching, the overall impact of OSA on length of ICU stay was not significant (p = .24). In a predefined subgroup analysis, there was a significant impact of OSA on the length of ICU stay for patients with BMI over 40 kg/m² (IRR: 1.56 [1.05; 2.32], p = .03). OSA status had no impact on ICU or hospital mortality and VAP.

In general, known OSA did not increase the ICU stay except for patients with both OSA and morbid obesity.