Abstract Body: Introduction/Background
Rapid Response Teams (RRT) have been widely implemented to recognize and manage clinical deterioration outside of the intensive care unit (ICU). Hospital systems frequently rely on individual healthcare provider’s skill and attention to identify early deterioration and activate the appropriate clinical resources. This is referred to as the afferent limb, or triggering mechanism, of the Rapid Response system.

Hypothesis
Afferent limb failure leads to delayed clinical intervention and potentially worse outcomes for patients that progress to in-hospital cardiac arrest (IHCA).

Goals/Aims
The aim of this retrospective study was to identify if afferent limb failure, defined as failure to recognize two or more standardized early warning criteria in the 24 hours prior to non-ICU IHCA, is associated with increased in-hospital mortality when compared to patients with zero to one standardized early warning criteria.

Methods
Non-ICU IHCAs over a 6-year period (January 1^st, 2018, to December 31^st, 2023) at a large academic medical center were reviewed using standardized criteria to determine 1) if any RRT activation criteria had been met in the 24 hours prior to non-ICU IHCA, 2) how many RRT criteria were met, 3) whether an RRT activation occurred, and 4) in-hospital mortality. Statistical analysis included a Chi-Square analysis and Pearson Correlation Coefficient.

Results
We identified 386 adult non-ICU IHCAs, with 214 (55.4%) meeting at least two RRT criteria in the 24 hours preceding their non-ICU IHCA. In patients without a preceding RRT activation (N=313), there was significantly higher in-hospital mortality in patients who met two or more RRT criteria prior to their non-ICU IHCA than patients who met one or zero criteria (91/151, 60.2% vs 114/162, 70.3%, p < 0.05). We also found a weak but statistically significant correlation between the total number of RRT criteria met prior to IHCA and in-hospital mortality (r=0.1331, p < 0.05).

Conclusion
Afferent limb failure is associated with higher in-hospital mortality in patients with multiple markers of clinical deterioration prior to non-ICU IHCA. There is also an association between in-hospital mortality and the total number of clinical deterioration criteria met prior to non-ICU IHCA.