Review of extra corporeal membrane oxygenation as a cardiac assist

1. EXTRA CORPOREAL
MEMBRANE OXYGENATION
(AS A CARDIAC ASSIST)
Dr Sandeep Chauhan
All India Institute of Medical
Sciences, New Delhi

2. ECMO - History
• John H. Gibbon 1935
• Dennis D. 1951
• C. Walton Lillehei `Cross-circulation` 1954
• Kolff WJ & Berk HT 1944
• Theodore Kolobow `Silicon polymers`
• J Donald Hill 1971

3. ECMO - Goals
• Increased tissue oxygen delivery
• Carbon dioxide removal
• Aerobic metabolism
• Promote lung `rest`
• Temporary pulmonary / cardiac
support

4. ECMO - Indications
1. Inadequate oxygen delivery:
-Acute myocarditis
-Chronic cardiomyopathy
-Failure to wean CPB
-Post operative CHF
-Refractory arrhythmias
-Cardiac arrest

5. ECMO - Indications
2. Profound hypoxemia
3. Profound cyanosis
4. Support during catheterization

6. ECMO – Contraindications
(Relative)
1. End-stage, inoperable, irreversible
disease
2. Neurological impairment
3. Uncontrolled bleeding
4. Extremes of size & weight
5. Inaccessible vessels on CPR
6. Residual lesions

7. ECMO - Circuit
- Types : Veno-venous & Veno-arterial
- PVC tubing : Neonate & infant 1/4"
Pediatric 3/8"
Adult ½ "
- Arterial cannulae : 8 Fr – 21 Fr
- Venous cannulae : 8 Fr – 29 Fr
- Kendall Double Lumen Cannula

9. ECMO - Circuit
Pumps : Roller
Centrifugal
Oxygenator : Silicon Rubber Membrane
Plastic Screen Spacer
Polycarbonate Core
0.4 – 4.5 m2 surface area

11. ECMO - Circuit
# COLLAPSIBLE BLADDER :
75 ml & 135 ml
# HEAT EXCHANGER

12. ECMO - Circuit
# BRIDGE

13. ECMO - Anticoagulation
• ACT :
180 to 220 sec (< 160 sec dangerous)
• Cannulation : 75 – 150 U/kg heparin
• Infusion : 25 – 50 U/kg/hour

15. ECMO – VA Circuit
BODY WT.
(KG)
2-5 5-10 10-20 35-70
TUBING 1/4" 1/4" 3/8" 1/2"
RACEWAY 1/4" 3/8" 1/2" 1/2"
OXYGENA
-TOR (m2)
0.8 1.5 2.5 4.5
CANNULA
ART (FR)
VEN (FR)
8-14
10-16
15-20
12-17
17-21
17-19
19-21
23
PRIME
PRBC
FFP
1 UNIT
50 ML
2 UNIT
½ UNIT
3 UNIT
½ UNIT
4 UNIT
1 UNIT

16. Circuit Complications
• Cannula
• Pump
• Bladder
• Oxygenator
• Heat exchanger
• Tubing
• Embolism

17. Cannula Complications
• Wrong size
• Bleeding
• Malposition
• Clotting
• Dissection
• Decannulation

18. Bladder Complications
• Inadequate return:
- Hypovolemia
- Increased Intra Thoracic Pr.
- Venous Cannula Occlusion
- Capillary Leak Syndrome
• Air Embolism:
- High FIO2
- Inlet Obstruction
- Gas – blood leak

19. Pump Complications
# Pump Failure
# Loss of Occlusion

20. Oxygenator Complications
-Thrombosis of Membrane, Inlet-outlet
port
-Fluid in gas phase
-Failing oxygenator:
• Decreased O2 /CO2 transfer
• Widened pre & post membrane gradient
• Increased hemolysis
•Coagulopathy

21. Heat Exchanger Complications
• Corrosion & leak
• Hemolysis, Dilution, Electrolyte
imbalance
• Sepsis
• Seizures, Hyponatremia, Hemolysis

22. Tubing Complications
-Loosening of junctions
-Rupture
-`Walking`

23. Patient Complications
1. RENAL FAILURE:
- Capillary leak syndrome
- Loss of auto-regulation
- Hemolysis

24. Patient Complications
2. HEMOLYSIS:
- Occlusion
- Coagulopathy

25. Patient Complications
3. INTRACRANIAL HEMORRHAGE:
- Gestational age < 35 weeks
- Birth trauma
- Thrombocytopenia
- Coagulopathy
- Sepsis
- Systemic heparinisation
- Systemic hypertension
- Seizures

26. Patient Complications
4. MYOCARDIAL STUNNING:
- Subendocardial ischemia
- Poor coronary filling
- Hypoxia –reperfusion injury

27. Patient Complications
5. PULMONARY HYPERTENSION:
- L→R shunt across PDA
- ↑ Pulmonary flow
- Pulmonary edema
- Decreased systemic perfusion
- Acidosis
- Renal failure

28. Thank you!