Causes of Chest Compression Interruptions During Out-of-Hospital Cardiac Arrest Resuscitation

Abstract

Background Interruptions in chest compressions contribute to poor outcomes in out-of-hospital cardiac arrest. The objective of this retrospective observational cohort study was to characterize the frequency, reasons, and duration of interruptions in chest compressions and to determine if interruptions changed over time. Methods and Results All out-of-hospital cardiac arrests treated by the Seattle Fire Department (Seattle, WA, United States) from 2007 to 2016 with capture of recordings from automated external defibrillators and manual defibrillators were included. Compression interruptions >1 second were classified into categories using audio recordings. Among the 3601 eligible out-of-hospital cardiac arrests, we analyzed 74 584 minutes, identifying 30 043 pauses that accounted for 6621 minutes (8.9% of total resuscitation duration). The median total interruption duration per case decreased from 115 seconds in 2007 to 72 seconds in 2016 (P<0.0001). Median individual interruption duration decreased from 14 seconds in 2007 to 7 seconds in 2016 (P<0.0001). Among interruptions >10 seconds, median interruption duration decreased from 20 seconds in 2007 to 16 seconds in 2016 (P<0.0001). Cardiac rhythm analysis accounted for most compression interruptions. Manual ECG rhythm analysis and pulse checks accounted for 41.6% of all interruption time (median individual interruption, 8 seconds), automated external defibrillator rhythm analysis for 13.7% (median, 17 seconds), and manual rhythm analysis and shock delivery for 8.0% (median, 9 seconds). Conclusions Median duration of chest compression interruptions decreased by half from 2007 to 2016, indicating that care teams can significantly improve performance. Reducing compression interruptions is an evidence-based benchmark that provides a modifiable process quality improvement goal.

Keywords: cardiac arrest; cardiopulmonary resuscitation; defibrillation; emergency medical services.

Figure 1

Patient inclusion criteria and initial rhythm status. CPR indicates cardiopulmonary resuscitation; EMS, emergency medical services; and OHCA, out‐of‐hospital cardiac arrest.

Figure 2

Median pause duration and frequency of common pause causes. The top 10 pause causes are plotted, showing median pause duration in seconds for each pause cause. Each dot represents one pause. We tested whether there was a temporal change in compression interruption using linear regression, examining the association between year as the independent variable and pause duration as the dependent variable. P values were adjusted for clustering of observations within incidents with the Huber‐White sandwich estimator. “Intubation” and “arrest recognition” have positive slopes but lack statistical significance over time. In a sensitivity analysis, the nonparametric Spearman ρ test was run and produced P values similar to those reported in the figure. AED indicates automated external defibrillator.

Figure 3

Change in cardiopulmonary resuscitation (CPR) fraction over time for initially shockable and nonshockable cases. Each dot represents a single case. We examined the association between time and CPR fraction for initially shockable and nonshockable cases with linear regression. P values were adjusted for clustering of observations within incidents with the Huber‐White sandwich estimator. The plotted linear regression lines show an association between time and increasing CPR fraction, for both the shockable initial rhythm (P<0.0001) and the nonshockable initial rhythm cohorts (P<0.024). There was a difference in trend in CPR fraction and time for shockable and nonshockable rhythm. Shockable rhythms were associated with lower CPR fraction over time (P<0.0001 by linear regression). AED indicates automated external defibrillator; BLS, basic life support; and HP‐CPR, high‐performance cardiopulmonary resuscitation.