Impact of rapid response system implementation on critical deterioration events in children.

Importance: Rapid response systems aim to identify and rescue deteriorating hospitalized patients. Previous pediatric rapid response system implementation studies have shown variable effectiveness in preventing rare, catastrophic outcomes such as cardiac arrest and death.
Objective: To evaluate the impact of pediatric rapid response system implementation inclusive of a medical emergency team and an early warning score on critical deterioration, a proximate outcome defined as unplanned transfer to the intensive care unit with noninvasive or invasive mechanical ventilation or vasopressor infusion in the 12 hours after transfer.
Design, Setting, and Participants: Quasi-experimental study with interrupted time series analysis using piecewise regression. At an urban, tertiary care children's hospital in the United States, we evaluated 1810 unplanned transfers from the general medical and surgical wards to the pediatric and neonatal intensive care units that occurred during 370,504 non-intensive care patient-days between July 1, 2007, and May 31, 2012.
Interventions: Implementation of a hospital-wide rapid response system inclusive of a medical emergency team and an early warning score in February 2010.
Main Outcomes and Measures: Rate of critical deterioration events, adjusted for season, ward, and case mix.
Results: Rapid response system implementation was associated with a significant downward change in the preintervention trajectory of critical deterioration and a 62% net decrease relative to the preintervention trend (adjusted incidence rate ratio = 0.38; 95% CI, 0.20-0.75). We observed absolute reductions in ward cardiac arrests (from 0.03 to 0.01 per 1000 non-intensive care patient-days) and deaths during ward emergencies (from 0.01 to 0.00 per 1000 non-intensive care patient-days), but these were not statistically significant (P = .21 and P = .99, respectively). Among all unplanned transfers, critical deterioration was associated with a 4.97-fold increased risk of death (95% CI, 3.33-7.40; P < .001).
Conclusions and Relevance: Rapid response system implementation reversed an increasing trend of critical deterioration. Cardiac arrest and death were extremely rare at baseline, and their reductions were not statistically significant despite using nearly 5 years of data. Hospitals seeking to measure rapid response system performance may consider using valid proximate outcomes like critical deterioration in addition to rare, catastrophic outcomes.