Prevalence of COVID-19 in Out-of-Hospital Cardiac Arrest

Abstract

◼ heart arrest T he first US case of coronavirus disease 2019 (COVID-19) was documented locally on January 20, 2020, with unrecognized viral transmission until the first death on February 26, 2020. 1 Resuscitation of patients in out-of-hospital cardiac arrest (OHCA), which depends on rapid, coordinated efforts involving laypersons, telecommunicators, prehospital professionals, and hospital providers, may be adversely affected by COVID-19 concerns.The American Heart Association published interim guidelines to help inform the conduct of bystander cardiopulmonary resuscitation (CPR) during the COVID-19 pandemic. 2These guidelines acknowledged the limited supporting science, including the prevalence of COVID-19 in people with OHCA.We aimed to estimate the frequency of COVID-19 among the total OHCA population.We undertook a cohort investigation of OHCA attended by emergency medical services (EMS) in Seattle and King County, Washington, from January 1 to April 15, 2020.Patients for whom EMS attempted resuscitation (EMS treated) and for whom EMS responded but did not provide resuscitation because of signs of irreversible death (dead on EMS arrival) were included.Our population-based OHCA registry systematically abstracts information about OHCA presentation, treatment, and outcome from dispatch audio recordings, defibrillator electronic data, prehospital and hospital records, death certificates, and medical examiner reports, organized according to the Utstein template.In this region of 2.2 million persons, EMS is a 2-tiered system, administered by Public Health-Seattle & King County, enabling direct engagement for comprehensive disease surveillance.The study was approved by the University of Washington Institutional Review Board.We undertook a hierarchical COVID-19 classification strategy that prioritized polymerase chain reaction (PCR) testing obtained before death or postmortem and clinical classification of a COVID-19-like illness (CLI) if PCR testing was not performed.Beginning in March, the medical examiner prioritized laboratory testing in decedents with an uncertain cause of death or respiratory symptoms before death.To identify patients with laboratory-confirmed COVID-19, we linked the state's COVID-19 surveillance system to EMS electronic records.For patients with EMS OHCA without PCR results, 2 authors (Drs Sayre and Rea) classified CLI status using EMS records by determining whether the arrest was preceded by febrile or respiratory illness or COVID-19 exposure.Disagreements were resolved by a third author (Dr Kudenchuk).Death certificates were processed using the US Centers for Disease Control and Prevention algorithm to classify death attributable to CLI.The interreviewer agreement of clinical CLI classification had a κ of 0.81.We performed a blinded review of EMS records in 98 cases with PCR results to determine the accuracy of clinical CLI classification.Using PCR results as a