Extracorporeal membrane oxygenation (ECMO)


Our adult acute severe cardio-respiratory failure (ASCRF) and extracorporeal membrane oxygenation (ECMO) cares for patients with:

  • acute severe respiratory failure who may need veno-venous ECMO (VV-ECMO)
  • acute severe cardiac failure, such as cardiogenic shock, who may need:
    • mechanical circulatory support (MCS) such as veno-arterial ECMO (VA-ECMO) and/or
    • peripheral ventricular assist devices (pVAD), such as Impella, oxyRVAD, IABP
    • other acute cardiac interventions

We provide:

  • advice on the management of patients with acute cardiorespiratory failure with rapid direct access to an experienced ECMO consultant and MDT
  • a specialised mobile ECMO (VV, VA and hybrid) retrieval service
  • specialist multidisciplinary services for patients with acute severe cardiorespiratory failure which include:
    • radiology
    • rheumatology
    • interstitial lung disease
    • lung inflammation service
    • obstetric
    • maternal medicine
    • cardiology
    • surgery
    • interventional radiology
    • infection disease

Making a referral

Before making your referral, please read the referral criteria and guidance. This includes details of the geographical area we take referrals from.

You can make referrals for ECMO at St Thomas' Hospital on the Signpost website. Please include a telephone number we can call you on in your referral.

Please call us us to discuss your referral.

After you have made your referral, we will review it and our on-call ECMO consultant will contact you to discuss. They'll usually contact you within 30 minutes of receiving a referral.

If we accept your referral, please read the ECMO checklist for referring hospitals.

Retrieval preparation checklist for referring hospitals

Please make sure all preparations are made before we retrieve your patient for a mobile ECMO. 

We'll bring all equipment and medicines with us, except controlled drugs which you'll need to provide. We'll draw these up before transferring back to Guy's and St Thomas' to avoid any syringe driver incompatibility.

Please prepare the patient for the ECMO by:

  • letting the patient's family know about the retrieval by our team
  • if possible, having the patient's family available to discuss consent
  • inserting a radial arterial line into the patient
  • leaving the patient's central line in its current position
  • drawing up and attaching your usual balanced crystalloid, your usual strength infusions of noradrenaline, sedatives and neuromuscular blockers to the patient
  • making sure all notes and charts have been photocopied and all imaging is on a CD or transferred electronically to us

Please provide:

  • a free theatre with an anaesthetist and scrub nurse available
  • a radiolucent theatre table
  • a c-arm in the theatre with fluoroscopy capability and a radiographer
  • at least 100ml of contrast for an intravenous injection
  • a vascular ultrasound in the theatre
  • 2 large empty surgical trolleys with drapes for sterile preparation of equipment
  • 1 small empty surgical trolley

Please provide:

  • a full blood count
  • electrolytes
  • creatinine
  • liver function tests
  • lactate
  • c-reactive protein (CRP)
  • partial thromboplastin time (APTTr)
  • international normalized ratio (INR)
  • fibrinogen
  • a chest X-ray
  • an electrocardiogram (ECG)
  • an echocardiogram if possible
  • current microbiology

Please crossmatch and have available:

  • 4 units of packed red cells, regardless of Hb
  • platelets, only if platelet count is less than 100
  • fresh frozen plasma (FFP), only if international normalized ratio (INR) or activated partial thromboplastin time (APPTr) is more than1.5

Referral criteria

VV ECMO is indicated for any potentially reversible, life-threatening form of respiratory failure that may benefit from lung rest, where:

  • cardiac function is adequate
  • the Murray score is 3 or more
  • the pH is <7.20 due to hypercapnea

However, please discuss you referral with us in any circumstances so that we can advise and discuss individual cases.

Any patient being considered for VV ECMO must be discussed with the ECMO consultant.

We accept referrals for people aged 16 and over. If your patient is under 16  we must discuss with our children's services before admitting your patient. This  will help determine the most appropriate location to treat your patient (adult or children's ICU).

Absolute contraindications to VV-ECMO

  1. Severe (medically unsupportable) heart failure/cardiogenic shock
  2. Severe chronic pulmonary hypertension and right ventricular failure (mean pulmonary artery pressure approaching systemic blood pressure)
  3. Cardiac arrest (ongoing)

Relative contraindications to VV-ECMO

  1. Duration of conventional mechanical ventilation >7 days, with high inspiratory pressures (Pplat>30cmH20), high FiO2 (FiO2 >0.8)
  2. Severe immunosuppression (solid organ transplant recipients >30 days,)
  3. CPR duration >30 min without documented neurological recovery
  4. BMI <18 kg/m2

Mechanical circulatory support (MCS) such as VA-ECMO is indicated for potentially reversible, severe, refractory cardiogenic shock in patients who have failed conventional support therapies.

In cases where MCS is being considered as a bridge to decision on durable mechanical support/transplantation, patients should have no absolute contraindications to cardiac transplantation.

Any patient being considered for MCS must be discussed with the ECMO consultant.

Physiological indications for consideration of VA-ECMO (after 1 to 12 hours of commencement of inotropic support):

  1. persisting (>6 hours) lactate >3mmol/L and/or ScvO2 <50% due to cardiogenic shock
  2. persisting cardiac index <2.2L/min/m2 due to cardiogenic shock
  3. evidence of end organ dysfunction due to cardiogenic shock
  4. trans-thoracic echocardiography with left ventricular ejection fraction <30% or aortic velocity time integral (Ao VTI) <8-12 cm/sec.

We also provide an extracorporeal cardiopulmonary resuscitation (eCPR) service for select refractory cardiac arrests.

In eCPR, pVA-ECMO needs to be established within 60 minutes of an appropriate refractory cardiac arrest. Unfortunately this timeline isn't achievable in a local centre where CPR is ongoing at the time of referral. However, our oncall ECMO consultant is always happy to discuss individual cases particularly with:

  • malignant arrhythmias/electrical storms
  • unstable/recurrent return of spontaneous circulation (ROSC)
  • non-anoxic primary hypothermic arrests

Hybrid V-AV ECMO is indicated for potentially reversible, severe, refractory cardiogenic shock in patients with severe respiratory failure who either have or are anticipated to have cardiac failure resolving prior to respiratory failure, or who are escalated to additional mechanical circulatory support once already on VV-ECMO.

Absolute contraindications to VA-ECMO

  1. Any contraindication to cardiac transplantation, particularly in patients with likely limited reversibility to their cardiac failure
  2. Peripheral arterial disease, aortic dissection precluding cannulation
  3. Moderate or severe aortic valve regurgitation
  4. Uncontrollable massive bleeding
  5. Known cerebrovascular event within 6 months (haemorrhagic or ischaemic)
  6. CPR >30 minutes at commencement of cannulation
  1. Chronic medical comorbidity with a life expectancy of less than 12 months
  2. Progressive, non-recoverable heart disease and not suitable for transplant
  3. Progressive and non-recoverable respiratory disease and not suitable for transplant. In the case of patients on the lung transplant list, discussion with the patient’s lung transplant centre must be held prior to consideration of ECMO
  4. Chronic severe pulmonary hypertension
  5. Advanced malignancy
  6. Graft versus host disease
  7. Unwitnessed cardiac arrest
  8. Cachexia due to an underlying progressive chronic disease
  9. Bone marrow transplant recipients within 9 months of transplant

Last updated: September 2023

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