Objective:

To characterize the relationship between no-flow duration and prognosis in older adults experiencing cardiogenic out-of-hospital cardiac arrest (OHCA).

Approach:

• Study Design: Retrospective cohort study using a population-based, nationwide observational design from the All-Japan Utstein Registry.
• Data Collection: Analyzed registry data collected between January 1, 2010, and December 31, 2023, focusing on older adults aged 65 years or older with witnessed cardiogenic OHCA.
• Inclusion/Exclusion Criteria: Included patients aged 65+, witnessed cardiogenic OHCA, and received resuscitation by paramedics; excluded cases with non-cardiogenic rhythms, witnessed by EMS, implausible no-flow intervals, or no-flow intervals exceeding 30 minutes.
• Outcome Measures: Evaluated survival, 30-day Cerebral Performance Category score, and prehospital return of spontaneous circulation (ROSC).

Key Findings:

• No-flow time is inversely associated with favorable outcomes in older adults experiencing cardiogenic OHCA based on the study's analysis.
• Favorable neurologic outcomes are uncommon as no-flow time approaches 15 to 20 minutes, according to previous research.
• Older adults may have shorter no-flow duration thresholds for favorable outcomes compared to the general adult population, as suggested by the study's findings.

Interpretation:

Identifying a no-flow duration threshold could assist clinical decision-making during resuscitation attempts in older adults, as indicated by the study.

Limitations:

• The study is limited to cardiogenic OHCA, which may not generalize to other types of cardiac arrest.
• Potential variability in CPR quality provided by bystanders was not fully accounted for.

Conclusion:

The study aims to provide insights into the impact of no-flow duration on outcomes for older adults with cardiogenic OHCA.

Sources:

• All-Japan Utstein Registry