Glossary · Clinical
ECMO
Extracorporeal membrane oxygenation. A life-support technique that oxygenates blood outside the body when the lungs (or the heart) can no longer do the job.
ECMO (Extracorporeal Membrane Oxygenation) is a heavy-duty critical-care technique that temporarily takes over the function of the lungs, and sometimes the heart, when these organs are failing. For the most severe forms of hantavirus pulmonary syndrome — like the one observed in the French patient from the MV Hondius admitted to Bichat — ECMO is the last resort when conventional mechanical ventilation no longer suffices.
Principle #
A parallel oxygenated blood circuit #
The patient's blood is drawn through a cannula placed in a large vein (typically femoral or jugular), passes through an oxygenation membrane where it picks up oxygen and releases CO₂, and is returned to the circulation. The pump that drives the blood is external, and the circuit runs for several days.
Two main modes #
- V-V ECMO (veno-venous): oxygenated blood is returned to the venous system. Indication: pure respiratory failure without major cardiac involvement. The most common mode for ARDS.
- V-A ECMO (veno-arterial): blood is returned into a major artery, bypassing the failing heart. Indication: refractory cardiogenic shock, sometimes combined with respiratory failure.
Indication in hantavirus disease #
Cardiopulmonary phase #
Hantavirus pulmonary syndrome causes rapid lesional pulmonary oedema (massive plasma extravasation into the alveoli) often coupled with cardiogenic shock. This phase, typically 4-10 days after symptom onset, is the main cause of death. Mechanical ventilation alone becomes insufficient when the oedema is diffuse and the PaO₂/FiO₂ ratio collapses.
Timing #
ECMO decision relies on standardised criteria: Murray score, RESP score, PaO₂/FiO₂, duration of conventional ventilation. Earlier ECMO initiation in the cardiopulmonary decompensation is associated with better outcomes. For hantavirus, Argentinian and Chilean teams recommend considering ECMO as soon as cardiogenic shock emerges, to avoid waiting for multi-organ failure.
Application to the MV Hondius #
French patient at Bichat #
On 12 May 2026, Prof. Xavier Lescure (infectious disease specialist, Bichat AP-HP) announced in a press conference that the French patient positive for Andes virus — repatriated from the MV Hondius via Tenerife — presented "the most severe form" of cardiopulmonary disease and was placed on ECMO. She is over 65 with comorbidities. This is the first French case placed on ECMO for this indication in the MV Hondius episode.
French ECMO capacity #
France has around 30 ECMO centres, several of them in the Paris region (Bichat, Pitié-Salpêtrière, Hôpital Européen Georges-Pompidou…) capable of handling patients in vital emergency. The REVA network coordinates inter-hospital transfers — including by helicopter or medical flight — to direct each patient to the appropriate centre.
Limits #
Invasive technique #
ECMO carries risks of bleeding (systemic anticoagulation is mandatory), infection (indwelling cannulas, prolonged ventilation), neurological complications (stroke on V-A ECMO) and thrombosis. In-hospital survival on V-V ECMO for severe ARDS sits around 50 % in the ELSO registry, all causes combined, but depends heavily on age, comorbidities and underlying aetiology.
Scarce resource #
ECMO mobilises highly specialised staff (intensivists, perfusionists, ECMO-trained nurses) 24/7, with costly equipment. Available ECMO beds are limited, making patient selection and regional coordination essential, especially in an epidemic context.
Key figures
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≈ 50 %
In-hospital survival on veno-venous ECMO for severe ARDS, all causes combined, per the international ELSO registry.
ELSO — Extracorporeal Life Support Organization Registry Report
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> 30
ECMO centres in mainland France, integrated in the REVA (European network of research on artificial ventilation).
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≈ 14 days
Average duration of veno-venous ECMO support for severe ARDS (international median, varies by cause).
Standards & references
- ELSO — Extracorporeal Life Support Organization — International scientific society that maintains the global registry of ECMO patients and publishes practice guidelines.
Frequently asked questions
What is ECMO?
ECMO (Extracorporeal Membrane Oxygenation) is a life-support technique that draws the patient's blood, oxygenates it through an external membrane, and returns it to the circulation. It temporarily replaces the function of the lungs (veno-venous ECMO, or V-V) and, in some cases, that of the heart too (veno-arterial ECMO, V-A). It is deployed in intensive care, in specialised centres.
When is ECMO used for hantavirus disease?
ECMO is considered in the most severe forms of hantavirus pulmonary syndrome, when conventional mechanical ventilation can no longer maintain adequate oxygenation. The cardiopulmonary phase of hantavirus disease can lead to massive lesional pulmonary oedema and cardiogenic shock — a classical ECMO indication. This was the case for the French patient admitted to Bichat Hospital and placed on ECMO on 12 May 2026, per Prof. Xavier Lescure (infectious disease specialist, Bichat).
How long can a patient stay on ECMO?
Typical duration of V-V ECMO for severe acute respiratory distress syndrome (ARDS) is 10 to 21 days, with an international median around two weeks. Longer durations (several months) are possible in exceptional cases, but complication risk (bleeding, infection, organ failure) rises with duration. Weaning is decided based on recovery of the patient's own lung function.
What is the prognosis on ECMO for hantavirus?
Data are limited by the rarity of the disease. South American clinical series suggest that ECMO significantly improves survival in the most severe cardiopulmonary forms of Andes virus infection, which would otherwise have a near-100 % case fatality rate. Prognosis depends on the delay from symptom onset to ECMO initiation, age, comorbidities and shock severity.
Further reading
- ELSO Registry — Extracorporeal Life Support Organization — ELSO (international registry)
- ELSO Adult Respiratory Failure Guidelines — ELSO (clinical guidelines)
- ECMO for hantavirus pulmonary syndrome (PMC) — PMC / NIH (scientific publication)