PROJECT SUMMARY/ABSTRACT Awareness with paralysis (AWP), or unintentional awareness, is memory recall during neuromuscular blockade (NMB) and can cause catastrophic psychological harm. Our team recently demonstrated a prevalence of AWP of 3.7% in mechanically ventilated emergency department (ED) patients, 25 times higher than that observed in the operating room (OR). Therefore, there is significant rationale to examine AWP in the ED, where 300,000 patients are mechanically ventilated annually. Post-traumatic stress disorder (PTSD) develops in up to 70% of patients who experience AWP, and ~ 35% of all critically ill ventilated patients. However, it is unknown to what degree mechanically ventilated ED patients develop PTSD symptoms. Further, though the overall experience drives PTSD development, knowledge of patient-centered experiences that can be targeted to improve outcome is lacking. Our long-term goal is to improve patient-centered outcomes in mechanically ventilated patients along the ED-to-ICU interface with pragmatic and scalable interventions aimed at prevention. To that end, the overall objective of this proposal is to conduct a pragmatic, stepped wedge cluster randomized trial in five academic EDs. The central hypothesis is that by using nudges and defaults aimed at reducing ED rocuronium use, the proportion of patients experiencing AWP will be significantly reduced. In addition, we hypothesize that the psychological burden suffered by mechanically ventilated ED patients is high, and modifiable targets can be identified with a mixed-methods approach. The scientific literature and our preliminary data provide the rationale for conducting this study, and through completion of its aims we will prevent an important threat to patient safety, and develop interventions to be tested in future trials in effort to improve mental health outcomes in survivors going forward. The public health impact from this proposal resides in the fact that it can be readily implemented broadly to prevent thousands of cases of AWP annually. In addition, by targeting the ED and examining psychological outcomes through a patient-centered lens, our results are expected to have a positive public health impact by elucidating the principal pathways of long-term psychological sequelae of critical illness and clarifying the role of time-sensitive ED interventions in contributing to those outcomes. This will allow us to develop specific, targeted countermeasures to improve long-term outcomes for critical illness survivors and identify promising prevention strategies for ED implementation.