What are considered poor prognostic factors in cardiac arrest?

In the context of cardiac arrest, poor prognostic factors are indicators that suggest a lower likelihood of successful resuscitation and favorable outcomes. Unwitnessed arrests present a significant challenge because immediate intervention is critical; delays can lead to poor outcomes due to prolonged periods without circulation. The absence of bystander CPR compounds this issue, as timely chest compressions can dramatically increase the chances of survival. Furthermore, a duration exceeding 30 minutes before effective resuscitation efforts are initiated typically indicates a severely diminished probability of recovery, as brain and other organ damage begins to occur after just a few minutes without oxygen.

Witnessed arrests, prompt CPR, and shorter durations of arrest actively contribute to improved outcomes, making them favorable factors rather than poor ones. Factors such as young age or high blood pressure with witnessed arrests usually indicate better prognoses, highlighting the importance of the immediate circumstances surrounding the arrest and the response to it.