Prehospital oxygen-therapy and mortality in patients treated by emergency medical services: a prospective, observational multicenter study.
World Journal of Emergency Medicine · 2025-07-01 · Observational study
Abstract
BACKGROUND: Oxygen supply is a common procedure performed by emergency medical services (EMS); however, whether prehospital oxygen or fraction of inspired oxygen (FiO2) therapy predict mortality has not been studied to date. This study aims to determine mortality associated with oxygen therapy in unselected patients with acute disease who underwent prehospital care. METHODS: This was a prospective, observational, cohort, multicenter, EMS-delivery, ambulance-based study. Adults with unselected acute disease who were managed by EMS and evacuated with high priority to the emergency department of four hospitals in three Spanish provinces. Epidemiological variables, on-scene vital signs, and prehospital blood analysis data were collected. The primary outcome was short- (2-, 7-, and 30-day), medium- (90- and 180-day), and long-term (365-day) all-cause cumulative mortality. The samples were a priori split according to thresholds of their received FiO2(FiO2=0.21, that is without oxygen therapy; FiO2 between 0.22 and 0.49; and FiO2≥0.5). The categorical variables FiO2, epidemiological variables, vital signs, prehospital point-of-care testing (POCT) and patient outcomes were fitted with a logistic regression model. Additionally, a propensity score matching and a survival analysis were used. RESULTS: The final sample included 7,494 patients, 70.3% of whom did not receive oxygen therapy, 15% with a FiO2 between 0.22 and 0.49, and 14.7% with a FiO2≥0.5. The 2-day mortality was 0.4%, 5.3%, and 22.9% respectively (P<0.001). The 365-day mortality was 9.9%, 33.1%, and 50.5% respectively (P<0.001). Finally, the FiO2 predictive capacities 2-,30-, and 365-day mortality were AUC=0.870 (95%CI: 0.840-0.899), 0.810 (95%CI: 0.784-0.837), 0.704 (95%CI: 0.679-0.728), respectively. CONCLUSION: Prehospital oxygen therapy by thresholds of FiO2 was linked to death and allowed mortality prediction. This finding could provide an aid for EMS providers, allowing to assess more individualized patient risk.
Abstract © the authors or publisher, via PubMed. Reuse and removal
Tags
Mortality & survival · Other drugs · Oxygen
Related articles
- High-flow nasal cannula oxygen therapy versus noninvasive ventilation in acute respiratory failure related to suspected or confirmed acute heart failure: a systematic review with meta-analysis. (Eur J Emerg Med, 2024)
- Mortality and morbidity in acutely ill adults treated with liberal versus conservative oxygen therapy (IOTA): a systematic review and meta-analysis. (Lancet, 2018)
- The association of prehospital systemic corticosteroids with emergency department and in-hospital outcomes for patients with asthma exacerbations. (Acad Emerg Med, 2024)
- High-flow nasal cannula oxygen versus noninvasive ventilation for the management of acute cardiogenic pulmonary edema: a randomized controlled pilot study. (Eur J Emerg Med, 2024)
- Standard vs. targeted oxygen therapy prehospitally for chronic obstructive pulmonary disease (STOP-COPD): study protocol for a randomised controlled trial. (Trials, 2024)
- The clinical journey of patients with a severe exacerbation of chronic obstructive pulmonary disease (COPD): from the ambulance to the emergency department to the hospital ward. (J Thorac Dis, 2022)