Lim BL, et al. - In this prospective observational study, researchers investigated predictors for hyperoxemia in acute exacerbation of chronic obstructive pulmonary disease (AECOPD) in Emergency Medical Services (EMS) and Emergency Department (ED). In Patient, Organization and Staff domains, they looked for a-priori candidate factors. Primary outcomes included key predictors for hyperoxemia. They also assessed hyperoxemic vs non-hyperoxemic groups with regard to in-hospital mortality and mechanical ventilation rates (secondary outcomes). Overall, they analyzed 326 patients, of whom, hyperoxemia was detected in 60.7%. Three eventual modifiable factors were identified, that included first ED SpO₂ > 95%, EMS non-rebreathing mask and ED nasal cannula. No difference was noted in secondary outcomes between groups.