LAUSR

Critical Care Medicine • Volume 46 • Number 1 (Supplement) www.ccmjournal.org Learning Objectives: Chest Compression Release Velocity (CCRV) during chest recoil is an understudied element of CPR performance. Our objective was to characterize CCRV during pediatric in-hospital cardiac arrest (IHCA). CCRV would be associated with differences in age and CPR duration, due to variations in chest configuration and compliance. Methods: Using a multicenter prospective observational cohort from 2015 to 2017, we analyzed pediatric (age < 18 yr) IHCA events of > 25 min with complete quantitative CPR metrics (ZOLL RSeries) across 12 sites. CCRV, measured using pad-integrated accelerometers, was defined as maximum velocity during chest compression (CC) recoil. CCRV was calculated for each CC and compared between 3 age categories and during early (min 3–8) vs. late (min 20–25) periods of CPR. Wilcoxon rank sum was used for comparisons. Results: Of 35 events with complete CC metric data and ≥25 min duration there were 12 (34%) < 1yo, 16 (46%) 1-< 8 yo, and 7 (20%) 8-< 18yo events, yielding 34,567 CCs. Median (IQR) duration was 46 min (38, 60). Median CCRV for < 1 yo: 155.2 (121.4, 213.9) mm/s; 1 to < 8 yo: 220.5 (172.7, 288.3) mm/s; 8 to< 18 yo: 381.5 (286.5, 448.1) mm/s. Difference in CCRV between age groups was significant (p < 0.001) with CCRV increasing as age increased. Overall median CCRV was 226.3 (160.3, 341.1) mm/sec and early CCRV was faster than late (221.2 [159.3, 305.3] mm/sec vs. 214.4 [155.2, 311.9] mm/sec, p = 0.004). Conclusions: We characterized CCRV during pediatric IHCA as a metric of CPR performance related to chest recoil. CCRV was significantly faster during early (min 3–8) vs late (min 20–25) CPR in events > 25 min duration. CCRV was significantly slower for < 1 yo, faster for 1 to < 8 yo, and fastest for 8 to < 18 yo. These findings suggest differences in chest compliance related to patient age and as a function of CPR duration.