Chest compression release velocity: Association with survival and favorable neurologic outcome after out-of-hospital cardiac arrest

Purpose: We evaluated the association between chest compression release velocity (CCRV) and outcomes after out-of-hospital cardiac arrest (OHCA). Materials and methods: CPR quality was measured using a defibrillator with accelerometer-based technology (E Series, ZOLL Medical) during OHCA resuscitations by 2 EMS agencies in Arizona between 10/2008 and 06/2013. All non-EMS-witnessed adult (≥18 years) arrests of presumed cardiac etiology were included. The association between mean CCRV (assessed as an appropriate measure of central tendency) and both survival to hospital discharge and neurologic outcome (Cerebral Performance Category score. =. 1 or 2) was analyzed using multivariable logistic regression to control for known and potential confounders and multiple imputation to account for missing data. Results: 981 OHCAs (median age 68 years, 65% male, 11% survival to discharge) were analyzed with 232 (24%) missing CPR quality data. All-rhythms survival varied significantly with CCRV [fast (≥400. mm/s). =. 18/79 (23%); moderate (300-399.9. mm/s). =. 50/416 (12%); slow (<300. mm/s) 17/255 (7%); p<. 0.001], as did favorable neurologic outcome [fast. =. 14/79 (18%); moderate. =. 43/415 (10%); slow. =. 11/255 (4%); p<. 0.001]. Fast CCRV was associated with increased survival compared to slow [adjusted odds ratio (aOR) 4.17 (95% CI: 1.61, 10.82) and moderate CCRV [aOR 3.08 (1.39, 6.83)]. Fast CCRV was also associated with improved favorable neurologic outcome compared to slow [4.51 (1.57, 12.98)]. There was a 5.2% increase in the adjusted odds of survival for each 10. mm/s increase in CCRV [aOR 1.052 (1.001, 1.105)]. Conclusion: CCRV was independently associated with improved survival and favorable neurologic outcome at hospital discharge after adult OHCA.