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.