To our knowledge, this is the first report describing implementation of an in situ “mock code” simulation program in a pediatric cardiac acute care unit. Improved code team performance as measured by decreased time to epinephrine during simulation exercises, and actual cardiac arrests, was observed over time. Since implementation of the program in 2015, ROSC and survival to hospital discharge after cardiac arrest in the PCACU have improved significantly. Because IHCA occurs more frequently in children with cardiac disease, and because mock code exercises are resource-intensive, the PCACU may represent a high yield setting (outside of the ICU) to focus in situ simulation training initiatives.

Previous studies describing in situ simulation training in children’s hospitals and its impact on CPR performance and IHCA patient outcomes have demonstrated mixed results [10, 12, 13]. These studies performed simulation exercises across multiple units throughout their respective hospitals. Andreatta et al. reported improved survival after IHCA following implementation of a hospital-wide, simulation-based mock code program. Importantly, the location of IHCA events was not reported in this study and thus it is not clear if improved survival was observed in non-ICU environments. Over 90% of pediatric IHCA occurs in an ICU, which in some ways makes it an easier environment to improve CPR performance and outcomes [14]. Moreover, facilitating and debriefing in situ simulation exercises is resource-intensive, and a large-scale effort across the entire hospital may not be feasible, or sustainable, at some centers. Ensuring that every nurse and physician is exposed to training would require frequent exercises in all units and large participant teams. Increasingly, hospitalized children with cardiac disease are being cared for in separate cardiac units with dedicated care teams [15,16,17]. Because of the inherent risk of this patient population, and the resource-intensive nature of the intervention, the pediatric cardiac acute care unit may be a valuable location for a more targeted approach to implementing a mock code program.

Time to the first dose of epinephrine during cardiac arrest has been associated with ROSC, neurologic outcomes, and survival to hospital discharge after pediatric IHCA in two large studies that utilized the Get With The Guidelines-Resuscitation (GWTHG-R) registry [5, 6]. Timely administration of epinephrine is unlikely to be helpful unless high-quality CPR, effective code team leadership, and communication are performed [12]. Thus, the findings of Andersen and Raymond et al. suggest that time to epinephrine may represent a useful, objective, surrogate metric of overall code team performance.

This study has multiple limitations. Due to the small number of actual cardiac arrests and the potential for unmeasured confounders, we have been careful to designate the described improvements as observations rather than associations. Concurrent process improvement activities were implemented during the study period which could confound the findings. An early warning score and a dedicated rapid response team were developed and implemented in 2015. It is possible that these tools have allowed for earlier identification of patient deterioration in the PCACU, timelier interventions, and improved patient outcomes. However, these tools were developed to improve surveillance and prevent cardiac arrest, whereas in situ simulation training has focused on code team performance. Additionally, patient volume or acuity has not declined in the PCACU during the study period. To the contrary, patients on this unit have increasingly received therapies that are often associated with higher illness severity and include high flow nasal cannula, inotropic medications (e.g., milrinone, dopamine), prostaglandin E infusions, and ventricular assist devices. Increasing severity of illness in this unit may have inherently increased the proficiency of the care team over time, improved resuscitations, and confounded the findings. Lastly, the structure of our hospital code team has not changed significantly during the study period, but the utilization of ECPR has become more prevalent.

In conclusion, we have observed improved team performance during in situ simulation exercises and improved patient outcomes after cardiac arrest in the PCACU. We recommend focusing simulation training resources to this high-risk hospitalized patient population and using time to epinephrine as a surrogate outcome measure of code team performance.