Prognostic Impact of No-Flow Time on 30-Day Neurological Outcomes in Patients With Out-of-Hospital Cardiac Arrest Who Received Extracorporeal Cardiopulmonary Resuscitation.

Background: How the time sequence of cardiopulmonary resuscitation (CPR) procedures is related to clinical outcomes in patients with out-of-hospital cardiac arrest (OHCA) remains unclear. This study examined the impact of the time interval from collapse to start of CPR (no-flow time, NF time) and the time interval from start of CPR to implementation of extracorporeal CPR (ECPR) (low-flow time, LF time) on neurological outcomes.

Methods and results: During the period from 2010 to 2015, we enrolled 85 patients who received ECPR. Fourteen patients (16.5%) showed favorable 30-day neurological recovery. NF time was shorter in the favorable neurological recovery group than in the unfavorable recovery group (1.4±3.0 vs. 5.2±5.8 min, P<0.05), though combined NF+LF times were similar in the 2 groups (50.1±13.2 vs. 55.1±14.8 min, P=0.25). Multivariate logistic regression analysis indicated that pupil diameter at arrival and NF time were independently associated with favorable neurological recovery. The optimal cut-off value of NF time to predict favorable neurological recovery was 5 min (area under curve: 0.70, P<0.05; sensitivity, 85.7%; specificity, 52.1%).

Conclusions: The results suggest that NF time is a better predictor than NF+LF time for neurological outcomes in OHCA patients who received ECPR, and that start of CPR within 5 min after collapse is crucial for improving neurological outcomes followed by use of ECPR.