Contextualizing Pseudo-Pulseless Electrical Activity in Cardiac Arrest: A Meta-Analysis and Systematic Review

Nonshockable cardiac arrest rhythms have demonstrably poor outcomes. Pseudo-pulseless electrical activity (PEA), a subset of PEA in which visible cardiac contractility is present, is being described more frequently in recent literature. Physiology suggests that presence of cardiac motion even without a palpable pulse is energetically more favorable than true PEA, which is more like asystole. Therefore, we hypothesize that there is an increase in the survivability of PEA compared with asystole which may in part be due to a subset of pseudo-PEA.

A PICOST research question was generated which guided the composition of a systematic review and meta-analysis in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist.

A total of 494,355 patients were identified from 12 pieces of literature. Meta-analyses revealed an overall increased survivability of PEA compared with asystole (odds ratio [OR] 2.08, 95% confidence interval [CI] 1.52-2.86). When differentiating between location of arrest, PEA was more survivable in both in-hospital cardiac arrest and out-of-hospital cardiac arrest than asystole (out-of-hospital cardiac arrest OR 4.17, 95% CI 3.78-4.60, and in-hospital cardiac arrest OR 1.60, 95% CI 1.42-1.79). Finally, when comparing neurological outcome of PEA with asystole, PEA was more favorable (OR 3.32, 95% CI 1.39-7.94).

Pseudo-PEA may be one of the explanations attributed to better outcomes of PEA, especially neurological, due to the presence of cerebral and coronary flow. The presence of PEA likely requires evidence-based tailored management with presence of pseudo-PEA being more like a profound shock state. More evidence is required to investigate the true incidence of pseudo-PEA and its outcomes compared with true PEA.