AUTHOR=Li Tong , Zhou Dawei , Zhao Dong , Lin Qing , Wang Dijia , Wang Chao , Zhang Rongli 

TITLE=Impact of Oxygen Saturation on Mortality in Obese and Non-obese Critically Ill Patients With Mechanical Ventilation: A Retrospective Observational Study

JOURNAL=Frontiers in Medicine

VOLUME=9

YEAR=2022

URL=https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2022.839787

DOI=10.3389/fmed.2022.839787

ISSN=2296-858X

ABSTRACT=<sec><title>Background</title><p>The main aim of this study was to evaluate the effect of oxygen saturation on mortality in critically ill patients with mechanical ventilation according to obesity status.</p></sec><sec><title>Methods</title><p>We conducted an observational study in mechanically ventilated patients admitted to the ICU retrospectively. Demographic, arterial blood gas, ventilator setting, interventions, and peripheral oxygen saturation (Spo<sub>2</sub>) during the first 24 h were recorded and analyzed between non-obese and obese patients. The main exposure included Spo<sub>2</sub>, time-weighted mean Spo<sub>2</sub> (TWM-Spo<sub>2</sub>), and proportion of time spent in different Spo<sub>2</sub> (PTS-Spo<sub>2</sub>) levels. The primary outcome was hospital mortality. We used multivariable logistic regression models to assess the relationship between Spo<sub>2</sub> and mortality, as well as the interaction between PTS-Spo<sub>2</sub> and obesity status.</p></sec><sec><title>Results</title><p>A total of 25,100 patients were included, of which 10,564 (42%) were obese patients. After adjusting for confounders, compared with TWM-Spo<sub>2</sub> of 94–98%, TWM-Spo<sub>2</sub> of &lt; =88% (OR 3.572; CI [2.343, 5.455]; <italic>p</italic> &lt; 0.001) and of 89–93% (OR 1.514; CI [1.343, 1.706]; <italic>p</italic> &lt; 0.001) were both associated with higher risk of mortality. PTS-Spo<sub>2</sub> of 99–100% was associated with increased risk of mortality for obese patients (OR 1.028; 95% CI 1.010–1.046; <italic>p</italic> = 0.002; P<sub>interaction =</sub> 0.001), while PTS-Spo<sub>2</sub> of 89–93% was associated with increased risk of mortality (OR 1.089; 95% CI 1.051–1.128; <italic>p</italic> &lt; 0.001; P<sub>interaction =</sub> 0.001) for non-obese patients.</p></sec><sec><title>Conclusions</title><p>For obese and non-obese critically ill patients with mechanical ventilation, the impact of oxygen saturation on hospital mortality is different.</p></sec>