Low-flow time and outcomes in out-of-hospital cardiac arrest patients treated with extracorporeal cardiopulmonary resuscitation

INTRODUCTION

In out-of-hospital cardiac arrest (OHCA) patients with extracorporeal cardiopulmonary resuscitation (ECPR), the association between low-flow time, the duration between the initiation of conventional cardiopulmonary resuscitation and the establishment of ECPR, and outcomes has not been clearly determined.

METHODS

This was a secondary analysis of the retrospective multicenter registry in Japan. This study registered patients ≥18 years old who were admitted to the emergency department for OHCA and underwent ECPR between January, 2013 and December, 2018. Low-flow time was defined as the time from initiation of conventional cardiopulmonary resuscitation to the establishment of ECPR, and patients were categorized into two groups according to the visualized association of the restricted cubic spline curve. The primary outcome was survival discharge. Cubic spline analyses and multivariable logistic regression analyses were performed to assess the nonlinear associations between low-flow time and outcomes.

RESULTS

A total of 1,524 patients were included. The median age was 60 years, and the median low-flow time was 52 (42-53) mins. The overall survival at hospital discharge and favorable neurological outcomes were 27.8% and 14.2%, respectively. The cubic spline analysis showed a decreased trend of survival discharge rates and favorable neurological outcomes with shorter low-flow time between 20 and 60 mins, with little change between the following 60 and 80 mins. The multivariable logistic regression analyses showed that patients with long low-flow time (>40 mins) compared to those with short low-flow time (0-40 mins) had significantly worse survival (adjusted odds ratio 0.42; 95% confidence intervals, 0.31-0.57) and neurological outcomes (0.65; 0.45-0.95, respectively).

CONCLUSIONS

The survival discharge and neurological outcomes of patients with low-flow time shorter than 40 min are better than those of patients with longer low-flow time.

Impact of defibrillation with automated external defibrillator by bystander before defibrillation by emergency medical system personnel on neurological outcome of out-of-hospital cardiac arrest with non-cardiac etiology

Aim of the study

Although defibrillation using automated external defibrillator (AED) by bystander prior to emergency medical system (EMS) arrival was associated with favorable outcomes in out-of-hospital cardiac arrest (OHCA) of cardiac cause, whether it improves outcomes of OHCA due to non-cardiac cause is not clear. We aimed to investigate the impact of defibrillation with AED by bystander before defibrillation by EMS personnel on the outcomes of OHCA of presumed non-cardiac cause.

Methods

This was a retrospective cohort study using the All-Japan Utstein registry (reference period: 2013 to 2017). We included adult patients with OHCA of presumed non-cardiac cause, who had initial shockable rhythm, and who received witnessed arrest bystander cardiopulmonary resuscitation (CPR). Exposure variable was defibrillation with AED by bystander in comparison with initial defibrillation by EMS. Logistic regression analyses were conducted to assess the association between bystander AED shock and favorable neurological outcome (Cerebral Performance Category scale 1 or 2) at one month.

Results

Among the 1,053 patients included for analysis, 57 (5.4%) received bystander AED shock. There was no statistically significant difference in the rate of favorable neurological outcome at one month between groups [9 (15.8%) vs 109 (10.9%), p = 0.26]. Logistic regression analysis adjusted for characteristics, intervention, and time course of CPR showed no association between bystander AED shock and favorable neurological outcome [OR (95% CI): 1.63 (0.70-3.77), p = 0.25].

Conclusion

In this study, defibrillation with AED by bystander before defibrillation by EMS personnel was not associated with the favorable outcomes of OHCA of presumed non-cardiac cause.