ECMO Flashcards
What are the patient factors when considering ECMO
Age
comorbidities
Frailty
Patient Wishes
Anatomy
Need for interhospital transfer
What are clinical state indications for ECMO
Reversibility of disease
Duration of disease
Speed of progression
number of organ failures
Acute physiology / shock status
Actual diagnosis
What age is contraindicated for ECMO
> 75
65 is a relative contraindication
What conditions are contraindications of ECMO
End stage heart or lung disease without acceptance by relative transplant service
Multi-organ failure
What are favorable pathologies for VA ECMO
Fulminant myocarditis
Pulmonary embolism with cardiogenic shock
First presentation cardiomyopathy
Primary arrhythmogenic cardiomyopathy
Drug overdose with cardiac depression and no anticipated long term sequelae
Primary graft dysfunction post heart transplant
Ischemic VSD post AMI
What are high risk pathologies for VA ECMO
AMI complicated by cardiogenic shock – early reperfusion
Papillary muscle rupture/ mitral regurgitation with AMI
Failure to wean off cardiopulmonary bypass
Heart transplant recipient with acute rejection suitable for VAD/ re-transplant
What are unfavorable pathologies for VA ECMO
AMI complicated by cardiogenic shock – delayed or failed reperfusion
Heart transplant recipient with chronic rejection suitable for VAD/ re-transplant
Chronic cardiomyopathy not suitable for bridge to VAD (sepsis and/or renal failure)
HOCM associated heart failure
Restrictive chronic cardiomyopathy
Adult septic shock
Absolute contraindications for VA ECMO
Age >75
Terminal illness or non-treatable malignancy
Liver cirrhosis Child-Pugh B or C
Irreversible CNS injury
Chronic renal failure CKD 5 or dialysis
End-stage COPD
Chronic symptomatic cardiac failure (NYHA 3 or 4) and not a VAD/transplant candidate
ECMO initiation would not be in keeping with known patient wishes or that of the patient’s medical treatment decision maker
What is the clinical indication for VA ECMO
Patients in cardiogenic shock with a cardiac index and blood pressure that are refractory to less invasive support (i.e. Inotropes)
When is VV ECMO indicated
Respiratory failure
considered when unable to maintain SaO2 >88% or pH >7.20 with safe mechanical ventilation settings (Plateau Pressure ≤32 and Tidal Volume ≤6 ml/Kg (PBW)
What are favorable pathologies for VV ECMO
Community acquired pneumonia (infective cause), COVID-19
Aspiration pneumonitis
Status Asthmaticus
Primary graft dysfunction following lung transplant within 7 days
ARDS from drowning or transfusion
What are high risk pathologies for VV ECMO
Necrotizing pneumonia or focal infective lung disease
Pulmonary vasculitis (Goodpasture’s, ANCA-associated, other autoimmune)
Lung transplant recipient 7-30 days post-transplant
Traumatic injuries (Moderate TBI, hypoxia from chest injury to allow assessment, Bronchial tear with air leak and hypoxia, ARDS from direct chest trauma)
Drug/toxin related pulmonary disease
Unfavorable pathologies for VV ECMO
ARDS from non-pulmonary cause (e.g. burns, pancreatitis, infection)
Invasive aspergillosis
Pneumocystis jirovecii pneumonia
Lung transplant recipients >30 days and suitable for re-transplantation (see also bridge to transplant)
What is the difference between occlusive and non-occlusive pumps
Occlusive (roller pump): Insensitive to afterload
Non-Occlusive (Centrifugal pump): Pre-load dependent and afterload sensitive
What are the 3 different modes used with ECMO
VV
VA
VPA
How does VV ECMO work
Blood is accessed from the venous side of the circulation (typically from great veins) and returned to the venous side of the circulation (typically to the right atrium). This mode provides support for respiratory failure by providing non-pulmonary gas exchange.
How does VA ECMO work
blood is accessed from the venous side of the circulation (typically the right atrium), bypasses the pulmonary circulation and is returned to the arterial side of the circulation (aorta). This mode provides arterial circulation and organ perfusion despite native cardiac failure. This mode unloads right ventricular failure but does NOT unload left ventricular failure.
How does VPA ECMO work
blood is accessed from the venous side of the circulation (typically the right atrium) and returned to the pulmonary artery. This mode provides support for right ventricular failure and non-pulmonary oxygenation. Blood bypasses the right ventricle. Typically it is used to support transient right ventricular failure following insertion of a durable left ventricular assist device (LVAD).
How does VVA or VAV ECMO work
blood is accessed from the great veins and returned to BOTH the right atrium and aorta from a single pump and membrane oxygenator.
How does VA + VV ECMO work
blood is accessed from the great veins, pumped by separate pumps (to separate membranes) and returned to BOTH the right atrium and aorta.
When is a temporary RVAD indicated
It provides short-term right ventricular and respiratory support typically following permanent LVAD insertion.
Techniques to medically manage LV distention syndrome
Lower MAP to 60-70mmHg
High PEEP (15 to 25 cmH20)
Inotropic support for maintenance of pulsatility
Volume state reduction (fluid removal) if blood pressure and venous pressures adequate
Increasing VA ECMO flow
What are the parameters for adequate blood flow and oxygenation with ECMO
ECMO blood flow (+ native cardiac output) > 2.0 l/min/m2
MAP > 65 mmHg
SpO2 > 90%, Hemoglobin > 80 g/L
How should the pump be positioned in relation to the oxygenator
Slightly HIGHER
How is a pneumothorax treated in someone who is attached to VV ECMO
NOT treated unless causing a tension Pneumo causing hemodynamic compromise as the lack of flow can help reverse the air leak
What are the common ventilation patterns associated with VV ECMO
- Relatively high PEEP 10-15 cmH2O
- Low-levels of pressure control ventilation with driving pressures of 10 cmH2O or less
- Low respiratory rate 5-10 /min
- Inspiratory time may be increased beyond 1 second
- FiO2 should be ≤ 0.6 with adequate VV ECMO support
What is the standard anticoagulant in someone on ECMO
Heparin
In a non-bleeding patient, what should be the target numbers if on Heparin
Platelets to be maintained > 50,000
Systemic heparin APTT target is 50-70
How is anticoagulation managed on someone who is bleeding/post-op
*Aggressively replace all clotting element deficiencies
- Give cryoprecipitate to target fibrinogen > 1.5
- Give platelets to target count >80,000
- Give Prothrombin and FFP to target INR <1.3
Heparin should not be given until bleeding has stopped for 12-24 hours
What is the reversal agent for Heparin
Protamine
What is given to a patient experiencing HIT
Bivalirudin
How is early hemolysis detected
- A red tinge in the effluent of the CRRT or urine
- Increased plasma free hemoglobin
- Pump head thrombosis may become apparent (e.g. noisy pump head) before other signs
