1. Extracorporeal Membrane Oxygenation (ECMO): Indications and Management Strategy
David Spielvogel, MD
Surgical Director, Cardiac Transplant and Mechanical Circulatory Support
Gilbert Tang, MD, MSc, MBA
Cardiothoracic Surgeon, Transcatheter Heart Program
On behalf of the Cardiac Transplant and Mechanical Circulatory Support Team
Westchester Medical Center, Valhalla, New York

2. OBJECTIVES Understand the clinical indications for ECMO therapy
Identify procedural strategies and techniques of ECMO therapy
Discuss management strategy of ECMO in the ICU
Describe the ECMO experience at Westchester Medical Center

3. PHYSIOLOGY of ECMO Basic principle:
De-saturated blood is drained via a venous cannula, CO2 is removed, O2 added through an “extracorporeal” device (an oxygenator), and the blood is then returned to systemic circulation via another vein (VV ECMO) or artery (VA ECMO)

4. VV ECMO
Perfusate blood returned to systemic circulation via venous cannula – travels into right ventricle and next pulmonary vasculature and is returned to the systemic circulation
Volume removed = volume returned; therefore no net effect on CVP, ventricular filling, or hemodynamics
CO2/O2 content in arterial blood supply is that of the blood arriving to right ventricle + any effects from gas exchange from remaining pulmonary function

5. VA ECMO Replaces/augments both pulmonary and cardiac function
Perfusate mixes in the aorta with blood from left ventricle (arriving from compromised lungs); thus O2/CO2 content = content of blood returning from the circuit + that of pulmonary source;
Systemic blood flow = ECMO flow + pt’s own CO

6. Role of ECMO in Cardiogenic Shock
Bridge to recovery (BTR)
Bridge to decision (BTD)
Bridge to surgery
Bridge to long-term VAD
Bridge to transplant (BTT)

7. IABP in Cardiogenic Shock
Can initially stabilize patient
May not provide enough support
Requires a certain level of LV function
Limited by persistent tachycardia / arrhythmias
Does not unload the RV
Provides some pulsatile flow with ECMO

8. BRIDGE TO RECOVERY Indications Acute MI Acute decompensated HF
Post-cardiotomy syndrome
Acute myocarditis
Severe rejection in transplant
Takotsubo’s
Massive PE
Respiratory failure and ARDS 8

9. BRIDGE TO SURGERY Indications Mechanical complications of AMI
VSD
Severe MR from papillary muscle rupture
CAD requiring CABG
Massive PE with heparin failure 9

10. BRIDGE TO Long-term VAD
Indications
Unable to wean off ECMO
Difficult donor match for transplant
Not a transplant candidate => LVAD as Destination Therapy 10

11. BRIDGE TO TRANSPLANT Indications Unable to wean off ECMO
Transplant candidate
Easy donor match for transplant 11

12. Predictors of Poor Outcomes
Multiorgan dysfunction
ARDS with sepsis
Severe neurological injury
Long time interval between shock and initiating ECMO 12

13. CONTRAINDICATIONS Major CNS injury Multiorgan failure
Severe anoxia
Embolic or hemorrhagic stroke
Intracerebral hemorrhage
Multiorgan failure
Metastatic disease
Overwhelming sepsis

14. ECMO: How to do it

15. TWO TYPES OF ECMO: Veno-arterial bypass - supports the heart and lungs
Veno-venous bypass – supports the lungs only

16. ECMO – The Recent Past

17. Centrimag-ECMO

18. Equipment: Cannulas VV ECMO: VA ECMO Jugular vein, femoral vein
Artery:
Femoral
Axillary
Aorta

19. Equipment: Pump, Oxygenator
Thoratec Centrimag pump & motor
Centrimag console
Maquet Quadrox oxygenator

20. IABP PA Catheter Venous: percutaneous Arterial: Femoral percutaneous
CENTRIMAG
IABP
QUADROX
OXYGENATOR
Venous: percutaneous
Arterial:
Femoral percutaneous
Axillary graft
Aorta direct

21. R axillary artery
R femoral vein

22. Axillary vs Femoral Cannulation
Side-arm graft sewn on
Antegrade perfusion better for cerebral and aortic root oxygenation, especially when lungs not oxygenating
Increased afterload
Risk of arm hyper-perfusion
Percutaneous
Need antegrade stick for forward perfusion
Retrograde perfusion increases atheroembolic risk
Ad-mixing with cardiopulmonary circulation => indequate cerebral and aortic root oxygenation if lungs not oxygenating

23. Check arterial line pressure!
High line pressure risks hyperperfusion and bleeding at axillary site
Need to Y the arterial outflow:
Bi-axillary
Axillary + femoral
Indications
Patients with large BSA
Small axillary artery

24. ECMO Management

25. Anticoagulation
IV Heparin, target ACT of seconds to prevent clotting upon interference of blood with prosthetic surfaces and in stagnant areas.
If high bleeding risk, ACT s
Watch for platelet drop and heparin induced thrombocytopenia (HIT)

26. Monitoring an ECMO patient
Continuous cerebral SaO2
CVP, PAP, CO
CXR – assess pulmonary edema
SvO2: 75% in VA ECMO and 85-90% on VV ECMO considered adequate as long as CO normal
EtCO2 – measures return of native lung function
aBG, lactate – tissue perfusion
Urine output, fluid balance – renal function
Labs: renal, hepatic function
Platelet count

27. POTENTIAL RISKS Limb complications Infection Bleeding Brain
Surgical site
Non-pulsatile flow
Renal insufficiency
Peripheral ischemia
Limb complications
Arm hyperperfusion
Leg ischemia
Air in circuit
Pump malfunction
Clots in the circuits
Heat exchanger malfunction
Cannula dislodgement

28. Criteria for Weaning ECMO
Pulmonary edema resolved
Minimal inotropes / pressors
End-organ dysfunction nearly recovered

29. ECMO Weaning Protocol ICU OR Explant ECMO if appropriate
ECMO flow down to L/min for 5 min
Assess CVP, PAP, CO
TTE to assess LV, RV function OR
U heparin
ECMO flow down to 1 L/min
TEE to assess LV, RV function, septal position
Explant ECMO if appropriate

30. Special Note on ECMO & LVAD
Pts with LVAD need to balance flow with both LVAD and ECMO to optimize end-organ perfusion
TEE to check septal position, need to unload RV
After ECMO explant, LVAD flow needs to increase b/c of LV preload increases

31. Westchester ECMO Experience

42. ACS Shock on ECMO at WMC Patient Characteristics N = 21 (%)
Age (mean +/- SD)
61 +/- 14 years
Female
7 (33%)
Renal failure
1 (5%)
COPD
2 (10%)
PVD
4 (19%)
TIA / Stroke
History of MI
16 (76%)
History of CHF
8 (38%)
Cardiogenic shock
21 (100%)
Prior PCI
11 (52%)
Prior CABG
Ventricular tachycardiac/fibrillation
Cardiac arrest requiring resuscitation
10 (48%)
IABP or Impella support prior to ECMO
Predicted mortality from APACHE 4 score (mean +/- SD)
38 +/- 16%
- Catheterization laboratory
45 +/- 16%
- Operating room
36 +/- 16%

43. OUTCOMES Implant Data N = 21 (%) Location of ECMO implant:
- Catheterization laboratory
7 (33%)
- Operating room
14 (67%)
Site of arterial outflow:
- Percutaneous femoral (all placed in cath lab)
- Axillary (all placed in OR)
Duration of support (mean +/- SD)
9.0 +/- 7.5 days
OUTCOMES
30-day all-cause mortality
5 (24%)
30-day mortality by location of ECMO implant:
4/7 (57%)
1/14 (7%)
ECMO as bridge to:
- Recovery
9 (43%)
- CABG
- LVAD / Transplantation
2 (10%)
Prolonged ventilation
10 (48%)
Pneumonia
3 (14%)
Renal failure
1 (5%)
Stroke
Irreversible neurological injury
Multiorgan failure
Bleeding
Vascular injury
0 (0%)

44. CONCLUSIONS Rapidly evolving technology
Increasing array of indications
Excellent “tool” for ACS with cardiogenic shock
Shifting the paradigm of “bridge to recovery”
Presently investigating the “science” behind the clinical results