A BRIEF ACCOUNT ON THE ECMO MODES , USES, INDICATIONS

1. ECMO ( EXTRACORPOREAL
MEMBRANE OXYGENATION )
Chairperson - DR VENKATAMURTY
Moderator - DR PAVAN
Presenter - DR HARSHAVARDHAN
DEPT OF PEDIATRICS –AIMS – SAH & RC

2. • Introduction
• History
• Modes of ECMO
• Circuit & components
• Indications
• Contraindications
• Mechanism
• Complications
• Outcome

3. INTRODUCTION
• Extracorporeal membrane oxygenation (ECMO) is the
application of a modified cardiopulmonary bypass for neonates
in cardiac or respiratory failure not responding to conventional
measures or treatments.
• The term extracorporeal membrane oxygenation (ECMO) has
generally been replaced by ECLS – extracorporeal life support ,
reflecting an expanded role beyond oxygenation .
• ECMO has been offered to 35,000 neonates worldwide till date.

4. ECMO - A form of extracorporeal life support where an
external artificial circuit carries venous blood from the patient
to a gas exchange device (oxygenator) where blood becomes
enriched with oxygen and has carbon dioxide removed.
• The blood is then returned to the patient via a central vein
or an artery.
• In simple words it is called a ~ HEART - LUNG MACHINE ~
SOURCE : ECMO guidelines Alfred Health Update nov 2015

8. History of ECMO….
• John Heysham Gibbon Jr - 1953
• Jefferson Medical College Hospital
(Philadelphia)
• First successful use of
Cardiopulmonary bypass

10. • 1972 - Dr J Donald Hill
San Fransisco (CA)
• First successful adult ECMO
• 24/M - Polytrauma with ARDS

12. • 1975 - Robert Bartlett
• ELSO LOGO – elso estb. In 1989

13. • Extra corporeal Life Support is achieved by
- Draining venous blood
- Removing CO2
- Adding oxygen
- Returning to circulation
- Through either a vein or artery

16. MODES OF ECMO
ECMO can be categorized according to the circuit used
– Veno -arterial - VA ECMO provides both gas exchange and
circulatory support (Heart & Lung failure)
– Veno -venous –VA ECMO allows gas exchange
only (Isolated Lung failure)

17. 2525
DIFFERENT CONFIGURATIONS IN ECMO
Most common configurations:
• Veno-Venous ECMO (VV-ECMO):
• Used to support patients with severe respiratory failure refractory
to conventional therapies
• Blood is drawn from a central vein, passed through an ECMO machine
and then returned back via a central vein.
• Veno-Arterial ECMO (VA-ECMO):
• Used to support patients with severe cardiac failure (with or
without respiratory failure)
• Blood is drawn from a central vein, pass through an ECMO machine
and then returned back via a central artery.
ECMO guidelines AlfredHealth Update nov 2015

18. • Arterio-Venous ECMO (AV ECMO) :
An arteriovenous (AV) extracorporeal circuit that uses the patient’s
own arterial pressure or incorporates a pump to drive blood across an
oxygenator can partially support the respiratory system by effectively
removing carbon dioxide (CO2) (extracorporeal CO2 removal [ECCO2R]).
ECMO guidelines AlfredHealth Update nov 2015

20.  ECMO serves as a BRIDGING THERAPY and not a curative
therapy.
Used as a
• - bridge to recovery :– i.e., buying time for patient to recover
• - bridge to decision :- provide temporary support to patient
and allow clinicians to decide on the next step.
• - bridge to transplant :- provide support to patient while
awaiting suitable donor organ.

21. ECMO CIRCUIT & COMPONENTS
The basic components of ECMO
circuit includes
• - a blood pump
• - membrane oxygenator & heat
exchanger
• - controller
• - cannulas
• - tubings

23. FROM THIS
TO THIS

24. CENTRIFUGAL PUMPS :
• Roller pumps are now being
replaced by centrifugal pumps.
• The perfusion pressure is
controlled by RPM (0-4000 RPM)
• Can deliver flow upto 8 L/min
• Very reliable upto 21 days.

25. MEMBRANE OXYGENATOR :
• ECMO circuits have a gas
exchange device called
oxygenator, to add Oxygen and
remove CO2 from blood.

26. • Previously, silicon membrane
oxygenators were used which
are being replaced by Hollow
fibre PMP(polymethyl
pentene) membrane
oxygenators.
• These are extremely efficient at
gas exchange and demonstrate
minimal plasma leakage, low
resistance to blood flow.

27. GAS EXCHANGE :
OXYGEN exchange depends on :
• Type of membrane & diffusion
characteristics
• Thickness of the blood pathway
• Surface area of the membrane
• FiO2 in the gas phase
• Rate of blood flow
CO2 exchange depends on :
• Difference in CO2 conc. between
blood and gas
• Size of membrane
• Fresh gas flow
• Blood pathway thickness
• Blood flow rate

28. HEAT EXCHANGER :
• In adults, it is usually built within the oxygenator.
• In paediatric cases, it is connected separately after the
oxygenator in the circuit.
• It is used for temperature regulation of the
extracorporeal blood.

29. • Controller panel for pressure
monitoring and blood gas
monitoring

31. VENO-VENOUS ECMO (VV ECMO)
• Venous blood is accessed from large central veins, pumped through
the oxygenator and returned to the venous system near right
atrium.
• There are 4 configurations of VV-ECMO depending on the
cannulation
• sites.
a) Femoro-femoral
b) high flow
c) femoro-jugular
d) double lumen single canula (Avalon)

32. FEMORO-FEMORAL :
• Access cannula is inserted via the
femoral vein with the tip sited within
the IVC.
• Return cannula is inserted via
contralateral femoral vein with the tip
in right atrium.
• Advantages : quick and safe to insert,
easy to secure cannulae.
• Disadvantages : limited maximum flow
rates, often requires conversion to a
high flow configuration.

33. HIGH FLOW :
• Uses the same bi-femoral cannulation.
• An additional short access cannula is
inserted via the right internal jugular vein
with tip in svc.
• Advantages : allows higher circuit blood
flows as they draw blood from the great
veins (svc & ivc).
- It is required in severe cases of
respiratory failure when single access
canula circuit flow is inadequate to
maintain sufficient levels of gas exchange.

34. • Disadvantages :
-occupies 3 veins.
- relatively complex to secure and dress the jugular cannula.
- patient remains bed bound.
- potential source of air embolism and pressure injury.
ECMO guidelines AlfredHealth Update nov 2015

35. FEMORO-JUGULAR :
• Access cannula – via femoral vein
with tip sited just below the inferior
cavo-atrial junction.
• Return cannula – into right internal
jugular vein with the tip in lower
SVC.
• Advantages : nearly can provide
adequate support (5-7 l/min).

36. • Disadvantages :
- relatively complex to secure and dress the jugular cannula.
- requires two sterile fields to be done during ECMO
cannulation.
- access insufficiency can be more difficult to identify in early stages
without negative pressure monitoring.
ECMO guidelines AlfredHealth Update nov 2015

37. DOUBLE LUMEN /TWO STAGE SINGLE CANNULA ( AVALON ):
• Single cannula with two lumens for
access and return inserted via the
right internal jugular vein.
• Advantages : single vein
cannulation. Allows movement
from bed and ambulation.
• Disadvantages : care on insertion to
avoid right ventricular
placement/rupture. Difficult to
position return port towards the
tricuspid valve.

38. VENO-ARTERIAL ECMO (VA-ECMO)
• Venous blood is accessed from the large central veins, pumped through
oxygenator and returned to the systemic arterial system in the aorta.
• It provides support for severe cardiac failure with or without associated
respiratory failure.
• Different configurations of VA ECMO are :
-standard Femoro-Femoral
-emergency Femoro-Femoral
-High Flow
-Central : specialised cannula
-Central : Bypass cannula

39. STANDARD FEMORO-FEMORAL :
• Access cannula is inserted via femoral vein
with tip in right atrium.
• Return cannula : via common femoral artery
with tip lying in common iliac artery or
lower aorta.
• Advantages : provides full or partial cardiac
support.
• Disadvantages : risk of differential hypoxia –
may need conversion to high flow
configuration if native cardiac function
improves in the setting of significant
respiratory failure.

40. EMERGENCY FEMORO-FEMORAL :
• Similar to standard femoro-femoral but uses SMALLER cannula
which are quicker to insert in an emergency.
• Standard cannula : 21-25 Fr
Emergency cannula : 19-21 Fr
Advantages : faster to insert. Used for ECMO-CPR or in peri-arrest
patients.
Disadvantages : risk of differential hypoxia.
ECMO guidelines AlfredHealth Update nov 2015

41. HIGH FLOW :
• Uses the same bi-femoral
cannulation with additional access
cannula inserted via the right
internal jugular vein with tip in svc.
• Advantages : used to minimise
differential hypoxia when native
cardiac function improves.

42. TUBINGS :
• Depending on the heparin
coating, they are of 2 types :
• - regular
• - heparin coated

44. INDICATIONS
ECLS primarily used for critically ill term & late preterm
newborns with reversible respiratory/cardiac failure who have
failed appropriate maximum medical management with
ventilatory support ( conventional/high frequency),volume
expansion,inotropic/vasopressor support.

45. INDICATIONS
Meconium aspiration syndrome
Congenital diaphragmatic hernia
Respiratory distress syndrome
Persistent pulmonary HTN of newborn
Sepsis
Pneumonia
Barotrauma ( air leak syndromes )
Perinatal asphyxia
- Supportive in – cardiac failure owing to CHD, Post cardiotomy heart failure,
cardiomyopathy.

46. • Weight > 1.6 - 1.8kg, gestational age >32 -34 weeks. The cannula
size is determined by infants wt.
• A. Respiratory failure. The indications for neonatal ECMO are
(i) reversible respiratory failure and
(ii) a predicted mortality with conventional therapy great enough to
warrant the risks of ECMO.
ECMO is also considered in patients with life-threatening air leaks not
manageable with optimal ventilatory support and chest drainage.

47. Oxygenation index (OI) is a measure of the severity of
respiratory failure and is calculated as follows:
OI = mean airway pressure (MAP) × FiO2/PaO2 × 100.
It is essential to document OIs from serial blood gases over
time because the OI may vary.
ECMO indications vary among different centers. Commonly
used criteria include two OIs of >40 within 1 hour, one OI of
60 on high-frequency ventilation, or one OI of 40
combined with cardiovascular instability.

48. • For infants hospitalized where ECMO is not available, an
OI of 20 should prompt early outreach to an ECMO center
for potential transfer because prolonged ventilation at high
ventilator settings may worsen ventilator-induced lung
injury and worsen the overall outcome.

51. • Total anomalous pulmonary venous return (TAPVR) may mimic neonatal
respiratory distress syndrome (RDS), resulting from lung congestion in
the setting of inadequate drainage of the pulmonary veins in the left
atrium.
• In any neonate with respiratory failure, hypoxia, and bilateral opacities
on chest radiograph, TAPVR should be excluded prior to initiating
ECMO support.
• Once veno-arterial ECMO support is initiated, pulmonary blood flow is
reduced and the diagnosis of TAPVR may be difficult to make using
echocardiography alone; these patients may require cardiac
catheterization on ECMO to demonstrate presence or absence of
pulmonary veins entering the left atrium.

52. B. Cardiac failure. ECMO provides biventricular support for
neonates with cardiac failure. General indications are low
cardiac output (CO) despite maximal hemodynamic support or
cardiac arrest with a potentially reversible underlying
condition.
ECMO for congenital heart defects can be offered as a bridge to
definitive treatment until the newborn's condition has
stabilized. Other cardiac indications are failure to wean from
cardiopulmonary bypass, cardiomyopathy, and pulmonary
hypertension.

53. C. Rapid-response ECMO (ECMO-cardiopulmonary
resuscitation [E-CPR]. In the setting of a witnessed
cardiorespiratory arrest, ECMO can be offered in centers
with a rapid response team.
A readily “clear-primed circuit” (an ECMO circuit primed
with normal saline rather than with blood products) and an
ECMO team must be available 24 hours per day in order to
offer E-CPR. Effective cardiopulmonary resuscitation (CPR)
before cannulation is essential for a favorable outcome during
rapid-response ECMO.

54. • D. Ex utero intrapartum treatment (EXIT) to ECMO
procedure. The vessels are cannulated during a cesarean
section while the newborn remains on placental support.
Indications include severe congenital diaphragmatic hernia
(CDH), lung tumours, and airway obstructing lesions such
as large neck masses and mediastinal tumours.

56. ECMO inclusion criteria - Murray score
= average score of all 4 parameters
Parameter / Score 0 1 2 3 4
PaO2/FiO2 ≥300mmHg 225-299 175-224 100-174 <100
(On 100%
Oxygen)
≥40kPa 30-40 23-30 13-23 <13
CXR normal 1 point per quadrant infiltrated
PEEP(cmH2O) ≤5 6-8 9-11 12-14 ≥15
Compliance
(ml/cmH2O)
≥80 60-79 40-59 20-39 ≤19

57. CONTRAINDICATIONS.
ECMO should only be offered for reversible conditions.
Contraindications are considered to be lethal –
• Chromosomal disorder (including trisomies 13 and 18 but not
21)
• Irreversible brain damage,
• Grade 3 or greater Intraventricular hemorrhage (IVH)
• Intraparenchymal hemorrhage.

58. EXCLUSION CRITERIA
• Primary disease is irreversible (disseminated
malignancy)
• On ventilator >15 days
• Irreversible / indeterminate neurological prognosis
• Any immunosupressed state
• Already in multiorgan failure
• Pre-existing coagulopathy
• Severe pulmonary hypertension
• Severe aortic regurgitation
• Gestational age <32 weeks & b.wt <1600 gms.
- IVH
- severe coagulopathy,
- progressive chronic lung disease

59. ECMO MECHANISM
• It includes :
- INITIATION
- MAINTENANCE
- DISCONTINUATION

60. INITIATION
• Once it has been decided to initiate ECMO, the patient is anticoagulated with
i/v heparin and cannulae are inserted according to the ECMO configuration (
VV or VA ECMO)
Following cannulation, patient is connected to ECMO circuit, the pump started
with the flow of 20 ml/kg/min and gradually increased every 5- 10 min by 10
ml/kg/min to reach the desired flow.
• Gas flow to blood flow ratio is adjusted to 0.5 : 1 & start with FiO2 of
21%  100% FiO2.
• Once desired flow achieved, ventilator settings are brought down to
base line.
SOURCE : ECMO UPTODATE 2015

61. • Saline priming - Patients who are placed on ECMO emergently can be
started on a saline-primed circuit. Instead of blood products, the circuit
is primed with NS . In centers with rapid-response ECMO, a saline
primed, sterile circuit is always available, minimizing the time to
initiate ECMO therapy.
• The neonate's own blood volume is initially diluted with the normal
saline from the ECMO circuit. This causes a drop in hematocrit and a
transient decrease in oxygen-carrying capacity. The hematocrit is later
restored by using ultrafiltration and transfusing packed red blood cells
(PRBCs)

62. • Blood priming. Patients who are placed on ECMO nonemergently are
started on a blood-primed circuit. Orders for the initial prime of a
neonatal circuit are as follows: 500 mL of PRBC (cytomegalovirus
[CMV] negative, <7 days old), 200 mL of fresh frozen plasma (FFP), 2
units of cryoprecipitate, and 2 units of platelets (not concentrated).
Heparin and Tris-hydroxymethyl-aminomethane (THAM, also “Tris”)
buffer and calcium gluconate are added to the circuit.

63. • Reasonable targets
are :
- an arterial oxy Hb saturation of- >90% for VA ECMO,
>75% for VV ECMO
- A venous oxy Hb saturation of 70-80% for VA ECMO
- Adequate tissue perfusion as determined by arterial blood pressure,
venous oxygen saturation and blood lactate level.
ECMO therapy - ECMO pump flow rate is generally 100 to 120
mL/kg/minute in newborns. Sweep gas flow rate is 1.0 to 2.5
L/minute for a 0.8 m2 and 1.0 to 4.5 L/minute for 1.5 m2
membrane.

64. • A safety check is conducted every 4 hours. This safety check
includes searching for blood clots and circuit inspection for leaks.
Normothermia is maintained and temperature is regulated by
adjustments in the heat exchanger water temperature.
schedule for laboratory studies:
• (i) activated clotting time hourly
• (ii) lactate levels twice daily
• (iii) complete blood count, platelets, whole blood electrolytes,
ionized calcium, and creatinine twice daily

65. • (iv) antithrombin III (AT III) twice daily and prior to FFP
administration and 3 hours post-FFP administration
• (v) liver function tests, alkaline phosphatase, lactate dehydrogenase
(LDH), bilirubin, albumin, pre-albumin, and total protein every week.

66. MAINTENANCE & MONITORING:
• Once the initial respiratory and hemodynamic goals have been achieved,
blood flow is maintained at that rate.
• Continuous venous oxymetry, Pressure monitoring (MAP, prepump P, pre
and post oxygenator P), vital parameters (HR, RR, TEMP), Flow rates
(blood flow rate at 60-150 ml/kg/min), neurological status, vascular
status to be monitored.
• Anticoagulation is sustained during ECMO with a continuous infusion of
unfractionated heparin, titrated with activated clotting time(ACT) of 180-
210 sec.

67. WEANING & TRIAL OFF OF ECMO
• INDICATIONS :
- For patients with Respiratory failure, improvements in radiographic
appearance, pulmonary compliance and arterial oxyHb saturation.
- With cardiac failure, enhanced aortic pulsatility correlates with
improved left ventricular output.
- One or more trials of taking the patient off of ECMO should be
performed prior to discontinuing ECMO permanently.
SOURCE : ELSO General Guidelines Version 1.3 December 2015

68. • Decrease flow in steps to 1 L/min at FiO2 100% or decrease flow to
2L/min then decrease sweep gas FiO2 to maintain SaO2 >95%
• When SaO2 stable on these settings,
-VV ECMO trials are performed by eliminating all countercurrent sweep gas
through oxygenator. Blood flow remains constant, but gas transfer doesnot
occur. Ventilator settings are adjusted.
-VA ECMO trials need temporary clamping of both drainage and infusion
lines, while allowing to circulate through a bridge between the arterial and
venous limbs.
- VA ECMO trials are generally shorter duration than VV ECMO trials because
of higher risk of thrombus formation.
SOURCE : ELSO General Guidelines Version 1.3 December 2015

69. SPECIAL SITUATIONS DURING EXTRACORPOREAL
MEMBRANE OXYGENATION SUPPORT
• ECMO-circuit change ( change in premembrane pressure, extensive
thrombosed/clotted circuit)
• Lung biopsy (If pulmonary function does not improve after a
prolonged period (usually 1 to 2 weeks of ECMO support), a lung
biopsy can be performed through a thoracotomy
• Left-sided heart failure and left atrial decompression (If left
ventricular contractility is severely impaired, increase in both left
ventricular end-diastolic pressure and left atrial pressures -
significant pulmonary edema from left atrial hypertension and to
intravascular and intracardiac thrombosis secondary to stasis. LA-
decompressed (“vented”) into the venous side of the ECMO circuit.

70. COMPLICATIONS
• Mechanical causes
• Systemic causes
• Bleeding
• Thromboembolism
• Heparin induced thrombocytopenia (HIT)
• VV ECMO specific complications
• VA ECMO specific complications
• Neurological complications

71. • Mechanical causes include
• clots in the circuit (most common in oxygenator, bladder, and bridge)
• cannula problems
• oxygenator failure
• air in the circuit
• Causes for poor venous return from the patient to the ECMO circuit
include hypovolemia, pneumothorax.
• Poor catheter position, small venous catheter diameter, excessive
catheter length, kinked tubing, and insufficient hydrostatic column
length

72. • Cardiovascular - Hemodynamic instability during ECMO may be a
result of hypovolemia,vasodilation during septic inflammatory
response,arrhythmias, and pulmonary embolism, Volume overload.
• Renal - Renal failure may warrant dialysis, whereas fluid overload
may require hemofiltration during the ECMO run
• Neurologic - Sequelae resulting in neurologic damage often originate
from acidosis and hypoxia before commencement of ECMO
- Intracranial haemorrhage (most common)

73. •BLEEDING :
- Occurs in 30-40% of patients on ECMO
- Due to continuous heparin infusion and platelet dysfunction.
Treatment :
-maintaining platelet count > 1 lakh/mm3, target ACT reduces the
risk of bleeding.
- surgical exploration if major bleeding occurs.
- if bleeding occurs, decrease heparin infusion & maintain ACT at
160 sec.
- plasminogen inhibitors can be given but may increase risk of
circuit thrombosis.

74. THROMBOEMBOLISM :
• It is more common with VA ECMO
than VV ECMO as infusion is into
systemic circulation.
• A sudden change in pressure
gradient indicates thrombus
formation.

75. CANNULATION RELATED :
• Vessel perforation with
haemorrhage.
• Arterial dissection
• Bleeding
• Distal ischemia in VA ECMO
-Treatment : inserting distal
perfusion cannula in femoral
artery distal to ECMO cannula.

76. HEPARIN INDUCED THROMBOCYTOPENIA
• HIT can occur in patients receiving ECMO.
• When HIT is proven, heparin infusion should be replaced by
non-heparin anticoagulant.
- If heparin induced thrombocytopenia (HIT) is confirmed,
argatroban, a synthetic direct thrombin inhibitor, can
be used as an alternative anticoagulant during ECMO.

77. VV ECMO SPECIFIC COMPLICATIONS
•RECIRCULATION :
- Here, reinfused blood is withdrawn through the drainage cannula
without passing through the systemic circulation.
- The degree of recirculation determines the efficiency of ECMO in
providing oxygenation.
INTERVENTION :
- Increasing the distance between cannulae
- Use of single site double lumen cannula
- Addition of another drainage cannula
SOURCE : ELSO guidelines for management of recirculation May 2015

78. VA ECMO SPECIFIC COMPLICATIONS
• Pulmonary haemorrhage
• Cardiac thrombosis
- retrograde blood flow in the ascending aorta in VA ECMO.
- stasis of blood can occur if left ventricular output is not maintained
leading to thrombosis.
• Coronary or cerebral hypoxia
- coronary usually gets blood from native circulation (from LV)
- With compromised LV & LUNGS, relatively hypoxic perfusion
occurs.

79. THE HARLEQUIN SYNDROME (NORTH SOUTH SYNDROME)
• Saturation of upper part of the body is lower than that of lower
half.
• This is due to flow competition in the aorta
– recovering heart vs ECMO pump
High cardiac output from native recovering heart prevents the
retrograde flow of ECMO to perfuse upper part.
If pulmonary function is impaired :
-”BLUE HEAD” :deoxygenated blood of upper part
-”RED LEGS” : hyperoxygenated blood to lower part

80. In case of respiratory failure, flow competition in the aorta between the recovering native heart
and the extracorporeal circuit can lead to a “Harlequin” or “North–South” syndrome.
Christopher Lotz et al. Circulation. 2014;130:1095-1104
Copyright © American Heart Association, Inc. All rights reserved.

82. OUTCOME
• Survival - The ECLS database has reported the outcomes of ECMO
therapies worldwide since 1985. A total of 28,271 ECMO runs (84%
survival) for neonatal respiratory support were reported for neonatal
respiratory disorders through July 2015 .
• For the most recently recorded year, the most common indication for
ECMO therapy was CDH, followed by persistent pulmonary hypertension
of the newborn (PPHN), meconium aspiration syndrome (MAS), sepsis, and
neonatal RDS.
• Survival rates for these conditions at 7 years of age after completion of the
UK Collaborative ECMO trial was 33% in the ECMO group and 59% in the
conventional group

83. ECLS CENTERS
• There are 620 ECMO Centers in the world right now according to ECLS
REGISTRY 2017. and in INDIA total of 8 ECMO centers are available
1. Fortis –Bangalore
2. Narayana institute of cardiac sciences-Bangalore
3. Manipal –Bangalore
4. Apollo hospitals- Chennai
5. KIMS –Hyderabad
6. Max Superspeciality- New delhi
7. Dayanand medical college- Ludhiana
8. Riddhi Vinayak hospitals -Mumbai

84. References-
• Tricia lacy Gomella – neonatology
• Cloherty manual of neonatology
• ELSO Guidelines 2015

85. Thank you