To impact survival rates by 30%, emergency department (ED) workers should follow the Advanced Cardiovascular Life Support (ACLS) guideline of relying on end-tidal carbon dioxide (ETCO2) monitoring to ensure cardiopulmonary resuscitation (CPR) is high-quality. In a large tertiary care hospital-based ED, ETCO2 monitoring was not consistently utilized, despite workers having ACLS training and access to ETCO2 monitoring devices. The purpose of this project was to determine if high-fidelity ACLS simulation and ETCO2 monitoring training affected ED staff’s resuscitation self-efficacy and ETCO2 device application during clinical resuscitations. Twenty-eight interprofessional ED healthcare workers participated in high-fidelity adult cardiac arrest simulation scenarios. Paired-samples t-test results showed a significant pre-post simulation survey total average resuscitation self-efficacy improvement from 3.99 to 4.52 (t= 6.83, p < .001). Ten ED adult cardiac arrest events prior to simulation and twenty events post simulation were retrospectively analyzed for device utilization. Two-tailed paired-samples t-test results showed a non-significant improvement in device utilization (t= -1.96, p= .081), however utilization more than doubled from 20% to 45%. Overall, results indicated high-fidelity simulation can have a significant improvement in resuscitative confidence of ED workers, which in future studies may translate to higher survival rates for adults in cardiac arrest.