Extracorporeal Life Support (ECLS)

Extracorporeal Life Support (ECLS)

= 에크모, 체외막산소화장치 (ECMO, Extracorporeal membrane oxygenation)

Respiratory ECLS or Veno-Venous (VV) ECLS

Venous blood (>1.5L/min) is aspirated from the vena cava or RA, passes through the pump and oxygenator and is then pumped back to the RA. VV ECLS provides support for severe respiratory failure, there is no direct cardiac support with VV ECLS. VA ECLS can also be used for primary respiratory failure in patients with some degree of concomitant cardiac failure.

Respiratory or VV ECLS

VV ECLS is indicated in patients with potentially reversible, acute severe lung failure who continue to deteriorate despite optimal conventional support such as ‘lung protective’ mechanical ventilation (low tidal volumes, limited plateau pressures [Pplat]) or other advanced therapies (prone position, inhaled pulmonary vasodilators, high frequency oscillation). ECLS should be considered before refractory lung failure or multi-organ failure develops.

Pathologic conditions that may require VV ECLS:

  - ARDS

  - Severe Air Leak Syndrome

  - Pulmonary contusion

  - Inhalation Injuries (gastric contents, near drowning, smoke)

  - Status asthmaticus,

  - Airway Obstruction

  - Bridge to lung transplantation

  - Acute graft failure following lung transplant

  - Alveolar proteinosis

Standard criteria for starting VV ECLS:

1. Murray score >3 (see below)

2. Hypoxaemia: PaO2/FiO2 <10 on FiO2 0.9 or higher for >1 hr

3. Hypercapnia: PaCO2 >11 or pH <7.20 for >1 hr

4. Corrected Minute Ventilation: >10 L/min (surrogate marker of increased dead space: Min Ventilation x PaCO2/5.4)

5. Pplat >30cmH2O, in absence of high pleural pressures (e.g. abdominal distension)

6. Static Compliance of respiratory system: <20mls/cmH2O

7. Less than 7 days of high pressure mechanical ventilation

Contraindications for VV ECLS:

  - Progressive non-recoverable lung disease, not amenable to lung transplantation

  - Chronic severe pulmonary hypertension with right ventricular failure (consider VA

ECLS)

  - Severe cardiac failure / Cardiac arrest (consider VA ECLS)

  - Advanced malignancy

  - Chronic organ dysfunction

  - Lung Failure associated with bone marrow transplantation

  - Contraindication to anticoagulation therapy

  - Recent spinal cord or central nervous system trauma or haemorrhage

  - Mechanical ventilation with FiO2 >0.9 and Pplat >30 cmH2O for >7 days

  - Age >70 yrs

  - BMI >30, BMI < 5

  - Trauma with multiple bleeding sites

  - Significant immunosuppression

  - Recent diagnosis of haematological malignancy

* RESP score (점수가 높을 수록 좋다.)

* PRESERVE score (점수가 높을 수록 좋지 않다.)

...

Cardiac ECLS or Veno-Arterial (VA) ECLS

Venous blood is aspirated from the vena cava or right atrium (RA), passes through the pump and oxygenator and is pumped back to the aorta. The return arterial cannula may be placed in a peripheral (femoral artery) or central (ascending aorta) location. VA ECLS provides support for severe cardiac failure (often with associated respiratory failure).

Cardiac or VA ECLS

Veno-arterial ECLS is used for short-term support in patients with severe heart (or heart and lung) failure where volume therapy, vasoactive medication and intra-aortic balloon counterpulsation have failed to provide adequate systemic perfusion. The decision to deploy VA ECLS is often made emergently in patients with acute circulatory shock not responding to conventional support therapies, cardiopulmonary resuscitation or not weaning from intraoperative cardiopulmonary bypass. If possible, the patient should be reviewed by Cardiology, Cardiothoracic Surgery and Critical Care Medicine prior to deployment of VA ECLS.

Indices of tissue hypoperfusion include systemic hypotension, mental status changes, oliguria, core-peripheral temperature gradient, skin mottling, myocardial ischaemia and

increased serum lactate concentration. In patients with satisfactory arterial oxygenation and haemoglobin concentration, inadequate systemic perfusion can be inferred by mixed venous oxygen saturation less than 70%.

Pathologic conditions that may require VA ECLS:

  - Post-cardiotomy cardiogenic shock

  - Ischaemic cardiogenic shock

  - Witnessed cardiac arrest (ECPR: extracorporeal cardiopulmonary resuscitation)

  - Bridge to decision regarding suitability for therapy (e.g. revascularisation)

  - Bridge to longer term support (e.g. Ventricular Assist Device [VAD], transplantation)

  - Acute decompensation of Dilated Cardiomyopathy

  - Acute fulminant myocarditis

  - Massive pulmonary embolism

  - Valvular heart disease

  - Refractory arrhythmia’s (VT/VF)

  - Massive haemoptysis / pulmonary haemorrhage

  - Trauma (e.g. pulmonary / cardiac or major vessel)

  - Sepsis with profound cardiac depression

  - Overdose of cardiac depressant medication

  - Acute graft failure after heart transplantation

  - Anaphylactic shock

  - Congenital cardiac anomalies

Contraindications for Cardiac ECLS:

  - Progressive non-recoverable cardiac failure, not amenable to transplantation or VAD

  - Severe aortic valve regurgitation

  - Aortic dissection

  - Un-witnessed cardiac arrest (risk of ischaemic hypoxic encephalopathy)

  - Advanced malignancy

  - Chronic organ dysfunction

  - Contraindication to anticoagulation therapy

  - Recent spinal cord or central nervous system trauma or haemorrhage

  - Age >70 yrs (consider pre-morbid status)

  - BMI >30, BMI <15

  - Trauma with multiple bleeding sites

  - Significant immunosuppression

  - Recent diagnosis of haematological malignancy

* SAVE-score

* reference : Mater Misericordiae University Hospital

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2018. 11. 13 - SJH