Extracorporeal CPR for Refractory Cardiac Arrest

• In ICU
• Thu, 4 Sep 2025

Sudden cardiac arrest is a major global cause of death, with around 640,000 cases annually in the USA (350,000 out-of-hospital, 290,000 in-hospital). Survival remains low, typically under 10% for OHCA and 15–34% for IHCA, varying widely across countries.

Extracorporeal cardiopulmonary resuscitation (ECPR), which uses venoarterial ECMO during refractory cardiac arrest, may restore circulation when conventional CPR fails. However, ECPR is not standard care due to limited evidence, high costs, and resource demands, and is currently offered only in specialised centres. Guidelines suggest it may be considered as a rescue option for selected OHCA and IHCA patients when conventional measures are unsuccessful.

Cardiac arrest is defined as the absence of cardiac activity and circulation. While no universal definition exists for refractory cardiac arrest, ECPR studies generally classify it as failure to achieve ROSC within 5–30 minutes of advanced life support. ECPR involves vascular cannulation. This provides temporary extracorporeal gas exchange and circulatory support, maintaining cerebral and systemic perfusion while the underlying cause of arrest is addressed.

No RCTs have directly compared ECPR and CCPR for IHCA. Observational studies show higher survival and better neurological outcomes with ECPR. For example, in one study (n=135), survival to discharge after ECPR was 34%, with better outcomes in those with shorter CPR durations, but survival persisted even beyond 60 minutes of CPR (8%). Another study (n=172) found significantly higher survival with ECPR (29% vs 12%) and better neurological outcomes, though significance was lost after propensity matching. Meta-analyses of observational data suggest ECPR lowers in-hospital mortality and that most survivors have favourable neurological recovery.

For OHCA, the ARREST trial (n=30, early termination) showed clear benefit of ECPR (43% vs 7% survival). The Prague OHCA and INCEPTION trials did not show significant primary outcome benefit, partly due to logistical delays, crossovers, and variable system designs. Faster cannulation and centralised systems (as in ARREST and Prague OHCA) yielded better outcomes compared to multicentre systems with longer low-flow times (INCEPTION). Secondary and pooled analyses show favourable trends for ECPR, especially in shockable rhythms: survival with good neurological outcome. Meta-analyses suggest ECPR improves survival and neurological outcomes in OHCA, with recent updates showing significant benefit.

Overall, evidence for IHCA relies on observational data but indicates potential survival and neurological benefit. For OHCA, RCTs show mixed results, but pooled analyses and meta-analyses suggest ECPR may improve outcomes, especially when implemented rapidly in high-volume, experienced centres.

ECPR can be life-saving in cardiac arrest due to severe poisoning. Observational data show survival to discharge around 31–56% depending on the cohort, with pooled analyses of 236 patients reporting 48% survival. Guidelines recommend venoarterial ECMO or ECPR as rescue therapy in severe intoxication.

In accidental hypothermia, survival after ECPR varies widely (42–100%), with neurologically favourable outcomes higher than in cardiac-cause OHCA, especially at body temperatures below 32°C. Outcomes are poorer in hypothermic avalanche victims and drowning-related cases.

In pulmonary embolism,  ECMO, including ECPR, can support patients with massive PE causing cardiogenic shock or arrest, with survival >60% in selected cases. Guidelines suggest ECMO may be considered with surgical or catheter interventions in refractory collapse, though evidence is limited and mostly retrospective.

ECPR may improve outcomes when combined with targeted interventions in conditions such as electrical storm (with catheter ablation) or IHCA after cardiac surgery (with resternotomy ± coronary angiography).

Overall, ECPR can be particularly beneficial in select reversible causes of cardiac arrest, but outcomes are highly context-dependent.

As far as patient selection for ECPR is concerned, no universally accepted criteria exist. High costs, resource intensity, and limited personnel restrict availability. Mortality after ECPR is high, reflecting disease severity, and strict selection may improve outcomes but exclude some patients who might benefit. Key factors for consideration include age, witnessed collapse, bystander CPR, signs of life during CPR, initial rhythm, cause of arrest, comorbidities, and time to ECPR initiation.

Older age is associated with poorer outcomes, though survival even in advanced age is possible. Data show very low survival in patients >75 years in Japan (~1.7%), but some single-centre cohorts report neurologically favourable survival up to 18–28% in older patients.

Shockable rhythms are linked to better outcomes than non-shockable rhythms. Non-shockable rhythms generally have lower survival; asystole fares worse than pulseless electrical activity (PEA). Signs of life during CPR, small pupil size (<5 mm), or transient ROSC before ECMO are associated with better outcomes in non-shockable rhythms.

ECPR should be considered early in the chain of survival, as shorter low-flow times are strongly associated with neurologically favourable outcomes. Premature initiation, however, risks exposing patients to unnecessary intervention if ROSC could be achieved with conventional CPR. Analyses suggest transporting OHCA patients for ECPR is optimal between 8–24 minutes of pre-hospital CCPR. Door-to-needle time and transport duration critically impact total low-flow time and survival.

Immediate post-arrest care is essential for successful ECPR outcomes, though standardised protocols are not yet established and evidence is limited. Endotracheal intubation may be preferable to supraglottic devices during resuscitation. Right-arm arterial lines are recommended to monitor coronary and cerebral perfusion, guide vasopressor therapy, and detect dual circulation. Bedside ultrasound helps verify cannula placement, detect complications, and assess cardiac function.

ECPR involves complex, high-risk management requiring vigilant monitoring for cannulation issues, cardiac dynamics, oxygenation, and bleeding/thrombosis.

The goal of ECPR is complete recovery with favourable neurological outcomes, while neuroprognostication should be carefully timed, and life-sustaining therapy decisions should avoid premature withdrawal. Long-term outcomes after ECPR can be favourable, with good survival, functional status, and quality of life in most survivors, though some patients may face ongoing limitations or require end-of-life decisions if recovery is not possible.

ECPR is also expensive and resource-demanding, with limited accessibility and uncertain cost-effectiveness, heavily dependent on system-level organization and specialized expertise.

Overall, ECPR holds promise for selected refractory cardiac arrest patients, but its application is currently limited to specialised centres, and further research is essential to clarify its benefits, optimise care, and ensure equitable access.

Source: The Lancet

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