# 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.

Canonical source: https://hantatracker.fr/en/glossary/ecmo/

**Aliases**: extracorporeal membrane oxygenation, artificial lung, V-V ECMO, V-A ECMO

**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](/en/glossary/syndrome-pulmonaire-a-hantavirus/) — 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](/en/glossary/syndrome-pulmonaire-a-hantavirus/) 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.