External validations of multimodal existing Termination of Resuscitation (TOR) rules for patients with out-of-hospital cardiac arrest in COVID-19 era

Aim: Futile resuscitation can lead to transmission risk of infection and unnecessary transports for out-of-hospital cardiac arrest (OHCA) in COVID-19 era The various existing termination of resuscitation (TOR) rules have been derivate and validated in North America and Asian countries This study aimed to evaluate the external validation of these rules in predicting survival outcomes for OHCA patients in COVID era Methods: A multicenter observational study was carried out using WinCOVID-19 Daegu registry data, collected between February 18 and March 31, 2020 The outcomes of each rule were compared to actual patient survival outcomes The sensitivity, specificity, false positive ratio (FPR) and positive predictive value (PPV) of each TOR rule was evaluated Results: Of total 184 OHCAs, overall 170 patients were enrolled and had cardiac arrest of presumed cardiac etiology TOR was recommended for 122 patients with the international BLS-TOR rule, with a specificity of 85% for predicting unfavorable survival outcomes, sensitivity 74%, FPR 0 8%, and PPV 99% When the traditional BLS-TOR and KoCARC TOR rule II were applied to our registry, one patient met TOR criteria but survived at hospital discharge With regard to criteria of FPR (upper limit of 95% CI 99%), only KoCARC BLS-TOR rule I, combining the factors of not being witnessed by EMT, an asystole at the scene, and no prehospital shock delivery or ROSC, was found to be the most superior of all the other TOR rules Conclusion: Among the previous nine BLS and ALS TOR rules, KoCARC BLS-TOR rule I was most suitable for predicting poor survival outcomes and showed improvement of diagnostic performances Further research into variations in resources and treatment protocols (e g , CPR quality, and post-cardiac arrest care) between facilities, regions and cultures will be useful for determining the feasibility of BLS-TOR rules for COVID-19 patients worldwide