Original ArticlesEffect of oxygen therapy on the risk of mechanical ventilation in emergency acute pulmonary edema patientsChu, Michael Yat Suna; Guo, Wenjiab; Lim, Kwee Kwangc; Lim, Beng LeongaAuthor Information aEmergency Department, Ng Teng Fong General Hospital bClinical Research Unit, Ng Teng Fong General Hospital cEmergency Medicine Department, National University Hospital, Singapore Received 21 June 2019 Accepted 5 August 2019 Correspondence to Michael Yat Sun Chu, MBBS, Emergency Department, Ng Teng Fong General Hospital, 1, Jurong East Street 21, Singapore 609606, Tel: +65 6716 5340; fax: +65 6716 5351; e-mail: Michael_Chu@nuhs.edu.sg European Journal of Emergency Medicine: April 2020 - Volume 27 - Issue 2 - p 99-104 doi: 10.1097/MEJ.0000000000000634 Buy Metrics Abstract Objective: We investigated the effects of hyperoxemia on morbidity and mortality in acute cardiogenic pulmonary edema (ACPE). Methods: We conducted a retrospective cohort study of patients in our emergency department (ED) with ACPE who received arterial blood gases. Patients were classified based on the first PaO2 as hypoxemic (<75 mmHg), normoxemic (75–100 mmHg) and hyperoxemic (>100 mmHg). The primary outcome was the rates of mechanical ventilation (MV). We also reported adjusted odds ratios (AOR) and their 95% confidence intervals (CI) of the primary outcome after adjusting for predictors of MV determined a priori. Secondary outcomes were median hospital length of stay (LOS) and in-hospital mortality. Results: We recruited 335 patients; 34.0% had hyperoxemia. The rates of normoxemia and hypoxemia were 27.5% and 38.5%, respectively. The rates of MV were: hypoxemic 60/129 (46.5%) vs. normoxemic 41/92 (44.6%) vs. hyperoxemic 50/114 (43.9%); P = 0.62. The AORs for MV for the hyperoxemic and hypoxemic groups (reference: normoxemic group) were 0.98 (95% CI: 0.53–1.79) and 1.38 (95% CI: 0.77–2.48), respectively. Intubation rates for the groups were: hypoxemic 15/129 (11.6%) vs. normoxemic 6/92 (6.5%) vs. hyperoxemic 12/114 (10.6%); P = 0.43. The secondary outcomes were comparable among the groups. In-hospital mortality rates were: hypoxemic 6/129 (4.7%) vs. 6/92 (6.5%) vs. 10/114 (8.8%); P = 0.42. Conclusion: Our exploratory study did not report effects on mechanical ventilation, median hospital LOS and in-hospital mortality from hyperoxemia compared to hypoxemic and normoxemic ED patients with ACPE. Further studies are warranted to prove or disprove our findings. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.