Early restricted oxygen therapy after resuscitation from cardiac arrest (ER-OXYTRAC): protocol for a stepped-wedge cluster randomised controlled trial.

INTRODUCTION: Cardiac arrest is a critical condition, and patients often experience postcardiac arrest syndrome (PCAS) even after the return of spontaneous circulation (ROSC). Administering a restricted amount of oxygen in the early phase after ROSC has been suggested as a potential therapy for PCAS; however, the optimal target for arterial partial pressure of oxygen or peripheral oxygen saturation (SpO2) to safely and effectively reduce oxygen remains unclear. Therefore, we aimed to validate the efficacy of restricted oxygen treatment with 94%-95% of the target SpO2 during the initial 12 hours after ROSC for patients with PCAS. METHODS AND ANALYSIS: ER-OXYTRAC (early restricted oxygen therapy after resuscitation from cardiac arrest) is a nationwide, multicentre, pragmatic, single-blind, stepped-wedge cluster randomised controlled trial targeting cases of non-traumatic cardiac arrest. This study includes adult patients with out-of-hospital or in-hospital cardiac arrest who achieved ROSC in 39 tertiary centres across Japan, with a target sample size of 1000. Patients whose circulation has returned before hospital arrival and those with cardiac arrest due to intracranial disease or intoxication are excluded. Study participants are assigned to either the restricted oxygen (titration of a fraction of inspired oxygen with 94%-95% of the target SpO2) or the control (98%-100% of the target SpO2) group based on cluster randomisation per institution. The trial intervention continues until 12 hours after ROSC. Other treatments for PCAS, including oxygen administration later than 12 hours, can be determined by the treating physicians. The primary outcome is favourable neurological function, defined as cerebral performance category 1-2 at 90 days after ROSC, to be compared using an intention-to-treat analysis. ETHICS AND DISSEMINATION: This study has been approved by the Institutional Review Board at Keio University School of Medicine (approval number: 20211106). Written informed consent will be obtained from all participants or their legal representatives. Results will be disseminated via publications and presentations. TRIAL REGISTRATION NUMBER: UMIN Clinical Trials Registry (UMIN000046914).

Thromboembolic events in hospitalised patients with COVID-19: ecological assessment with a scoping review.

OBJECTIVES: Thrombosis is a common complication of the novel COVID-19. Pre-COVID-19 studies reported racial differences in the risk of developing thrombosis. This study aimed to describe the geographical variations in the reported incidences and outcomes of thromboembolic events and thromboprophylaxis in hospitalised patients with COVID-19. The final search for randomised clinical trials was carried out in January 2022. Screening eligible articles and data extraction were independently performed in duplicate by multiple reviewers. DESIGN: Scoping review. MEDLINE, Embase, Cochrane Libraries were searched using terms related to COVID-19 and thromboembolism. SETTING: Hospitals all over the world. PARTICIPANTS: In-hospital patients with COVID-19. OUTCOME MEASURES: The incidence of deep venous thrombosis (DVT) and pulmonary embolism (PE), and the prophylactic anticoagulation therapy. RESULTS: In total, 283 studies were eligible, representing (239 observational studies, 39 case series and 7 interventional studies). The incidence of DVT was the highest in Asia (40.8%) and hospital mortality was high (22.7%). However, the incidence of PE was not very high in Asia (3.2%). On the contrary, the incidence of PE was the highest in the Middle East (16.2%) and Europe (14. 6%). Prophylactic anticoagulation therapy with low-molecular-weight heparin was the main treatment provided in all areas. Four of the seven randomised clinical trials were conducted internationally. CONCLUSIONS: The incidence of DVT was the highest in Asia. The incidence of PE was higher in the Middle East and Europe; however, detection bias during the pandemic cannot be ruled out. There were no major differences in the type or dose of prophylactic anticoagulants used for thromboprophylaxis among the regions.