<aside> 🧭
Chapter question: A patient is in cardiac arrest and the compressions are not working. What exactly is it that ECPR offers — and why do three randomised trials of the same intervention read as though they studied three different things?
</aside>
<aside> 📅
Evidence search date: 11 September 2026.
Primary sources: ECPR and Resuscitative ECMO (Shinar and Badulak), Chapter 2 — Optimizing the Pre-ECMO Resuscitation and Chapter 3, which supply the no-flow/low-flow framework and the low-flow outcome data; and ELSO Red Book 6th edition Chapter 32 — Extracorporeal Cardiopulmonary Resuscitation in Adult Patients, including Tables 32-1, 32-2 and the ECPR programme logistics table.
Retrieved in full from the publisher: the Bayesian meta-analysis of all three randomised trials (Critical Care 2024, DOI 10.1186/s13054-024-05008-9); the updated meta-analysis and trial sequential analysis (Critical Care 2024, DOI 10.1186/s13054-024-04830-5); and the trialists' own three-trial comparison (European Heart Journal: Acute Cardiovascular Care 2023, DOI 10.1093/ehjacc/zuad071).
The three randomised trials themselves — ARREST, PRAGUE-OHCA and INCEPTION — are published in journals this project cannot reach. Their designs, populations and results here come from structured abstracts and from the trialists' own comparative paper, which is written by authors from all three trials. Rows are marked Verified = No accordingly, and where the sources disagree with each other the disagreement is printed rather than resolved.
Currency warning. The ELSO ECPR interim guideline consensus statement (Richardson, Tonna, Nanjayya et al., ASAIO J 2021;67:221–228) predates none of the trials in publication but predates all of their synthesis. It remains the most recent society statement on ECPR, and the two randomised trials that reported after it — INCEPTION and the pooled individual-patient analysis — have not been incorporated into any updated guideline. This is the largest currency gap in this book.
</aside>
| This chapter owns | Deferred to |
|---|---|
| What ECPR is and how it differs conceptually from every other ECMO indication in this book; the no-flow/low-flow framework; what conventional CPR can and cannot deliver, and the physiological reason compression pauses are expensive; why time is the indication rather than a criterion; the sixty-minute rule and what it actually is; reperfusion as an intervention; what the three randomised trials each tested and why their results diverge; how to read the meta-analyses; the programme as the unit of intervention; and what Part III hands forward | Who is a candidate — age, rhythm, no-flow, signs of life, aetiology, exclusions → Chapter 20 |
| Cannulation under chest compressions → Chapter 21 | |
| The first hours after flow, coronary angiography, temperature, seizures → Chapter 22 | |
| Neurological assessment, imaging, biomarkers and prognostication → Chapter 23 | |
| Recognising futility, withdrawal and organ donation → Chapter 24 | |
| Resource allocation, cost and the ethics of offering ECPR at all → Chapter 77 | |
| Moving an ECPR patient between hospitals → Chapter 60 |
Every other ECMO decision in this book is taken about a circulation that exists. In severe ARDS the heart is beating and the question is gas exchange. In cardiogenic shock the heart is ejecting badly and the question is how much of the output to take over. Even in the sickest patient in Chapter 11, there is a blood pressure, a lactate trend, a neurological examination and — usually — a conversation.
In ECPR none of that is true. There is no native output. The pump is not supporting the circulation; from the first revolution it is the circulation. Three consequences follow, and they organise the whole of Part IV.
<aside> 🧠
Physiology — why ECPR is a different kind of decision
1. The indication is temporal, not physiological. Every ECPR candidate has the same physiology at the moment of decision: no cardiac output. What separates a candidate with a realistic chance from one without is not a measurement but elapsed time and what happened during it — how long there was no flow, how long there has been low flow, what rhythm started it, and whether anyone was compressing.
2. There is no pre-initiation baseline. Chapter 14 called the neurological examination before cannulation irreplaceable, because after cannulation the patient is sedated, anticoagulated and instrumented, and no later examination can be interpreted without it. In ECPR that baseline does not exist and never will. The single most important thing you would want to know about this patient is permanently unavailable. Chapters 23 and 24 exist because of this sentence.
3. The decision is made in minutes, by people with no history. There is no time to obtain records, no time to reach a family, and frequently no name. Chapter 20 is about making that decision reproducible in advance, because it cannot be made well in the moment.
</aside>
ECPR is offered for refractory cardiac arrest. The Red Book states the problem plainly: "Central to ECPR stands the definition of a refractory arrest. However, definitions differ (ranging between 10-60 mins) within the literature."
A sixfold range in the definition of the condition being treated is not a minor inconsistency. It means that two hospitals can both honestly report that they offer ECPR for refractory arrest and be treating populations with entirely different prior probabilities of benefit — and it means that when a study reports its results, the reader cannot assume that its patients resemble the patients in the next study. Much of the apparent disagreement in the ECPR literature is a disagreement about the word "refractory".
<aside> ⚠️
Danger — the bridge to nowhere
The ISCCM Manual names it directly: "A bridge to nowhere situation can be quite common."
ECPR restores circulation. It does not restore a brain, and it does not by itself treat the cause of the arrest. If the cause is not reversible and the brain has already been injured beyond recovery, the circuit converts a death in the emergency department into a death in the intensive care unit some days later, having consumed a cannulation, a bed, a team, and a family's hope.
Chapter 24 owns the exit. The decision to start must be taken by someone who already knows how it ends if it fails.
</aside>
The vocabulary of Part IV comes from the ECPR literature and is used precisely.
| Term | Definition | Why it matters for ECPR |
|---|---|---|
| No-flow | The interval between collapse and the start of chest compressions — the period during which an arresting patient received no bystander CPR | Pure ischaemia at normothermia. Nothing the hospital does later recovers it. It is the strongest single argument for excluding a patient, and the hardest interval to estimate reliably |
| Low-flow | The interval between the start of chest compressions and the return of spontaneous or extracorporeal circulation | This is the interval ECPR shortens. It is the only part of the timeline a system can modify, and every outcome gradient in this chapter is a gradient along it |
| Arrest-to-flow | Collapse to established extracorporeal blood flow — no-flow plus low-flow | The number a programme should audit itself on. It is the number the sixty-minute rule refers to |
"CPR is not a definitive therapy; it rarely produces sufficient cardiac output and gas exchange to sustain normal metabolic activity. Rather, conventional CPR is a mitigating bridge... The primary goal of conventional CPR is prolonging the window of tolerable ischemic insult."