Management of Infants
requiring Venovenous ECMO
Sixto F. Guiang, III
Dept. of Pediatrics
University of Minnesota
Neonatal ECMO = 73 % of all ECMO
VV ECMO = 20% of all Neonatal Pulmonary
University of Michigan
JAMA 2000;283:904-908
 N= 1000
 Newborns N=586
 Survival
 MAS
 CDH
 Others
 90% veno-venous
 9% IVH
88%
98%
68%
84-93%
VV ECMO

Respiratory Mode for all ages

Infants
20% of all Respiratory ECMO
 Approximately 800 cases / yr

Pediatric 28% of all Respiratory ECMO
 Approximately 200 cases / yr
Pediatric VV ECMO



Pediatr Crit Care Med 2003;4:291-298
Single Center 1991-2002
N = 82 ECMO for Respiratory Failure


Venovenous
Venoarterial

Unable to place VV
83%
17%
43%
Pediatric VV ECMO

Venovenous
 Dx
 ARDS
 RSV bronchiolitis
 Penumonia
 Outcomes
 Lower degree of respiratory failure
 Shorter ECMO (212 hour vs 350 hours)
 Higher survival (81% vs. 64%)
Pediatric VV ECMO
Pediatr Crit Care Med 2003;4:291-298
Infusion limb
Drainage limb
Inclusion / Exclusion
Guidelines- Same as VA








age of at least 34 weeks
Weight >1.5-2.0 kg
Potentially reversible process
Absence of uncorrectable cardiac defect
Absence of major intracranial hemorrhage
Absence of uncorrectable coagulopathy
Absence of lethal anomaly
Absence of prolonged mechanical ventilation with
high ventilatory settings
Oxygenation Failure
Criteria - VA and VV

Alveolar - arterial oxygen tension gradient
 [760 - 47)-paCO2] - paO2
 605 - 620 torr for greater than 4-12 hours

Oxygenation index
 Mean Airway Pressure x FiO2 x 100/ paO2
 > 35-60 for greater than 1-6 hours
Oxygenation Failure
Criteria - VA and VV

paO2



PaO2 < 35 for 2 hours
paO2 < 50 for 12 hours
Acute decompensation

paO2 < 30 torr
Myocardial Failure - VA Only

Refractory hypotension

Low cardiac output

pH <7.25 for 2 hours or greater

Uncontrolled metabolic acidosis secondary to
hemodynamic insufficiency

Cardiac arrest - CPR
Additional Exclusion Criteria Venovenous ECMO

Severe LV dysfunction
Severe hypotension
Cannulation during CPR

Desire to not have heparin



Bleeding
Additional Exclusion Criteria Venovenous ECMO

Use of vasopressors is NOT a
contraindication for VV ECMO

Isolated RV failure is NOT a
contraindication for VV ECMO
Vasopresor - VV ECMO
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



ASAIO Journal 2003;49:568-571
Neonatal ECMO-VA and VV
N = 43
Quantified inotropic support - Index
1 point = 1mcg/kgmin



Dopamine
Dobutamine
1 point = 0.01 mcg/kg/mon


Epinephrine
Norepinephrine
ASAIO Journal 2003;49:568-571
ASAIO Journal 2003;49:568-571
ASAIO Journal 2003;49:568-571
Infants with Inotropic Score > 10
ASAIO Journal 2003;49:568-571
ECMO Goals - VA and VV

Maintain adequate tissue oxygenation to
allow recovery from short term
cardiopulmonary failure

Adjust ventilator settings allowing for Lung
Rest minimizing further ventilator /oxygen
induced lung injury. Not necessarily lower
settings
ECMO Modes

Venoarterial - VA
 Blood drains-venous system
 Blood returns-arterial system
 Complete cardiopulmonary support

Venovenous - VV
 Blood drains-venous system
 Blood returns-venous system
 Pulmonary support only
Advantages of VA ECMO

Able to give full cardiopulmonary support

No mixing of arterial / venous blood

Good oxygenation at low ECMO flows

Allows for total lung rest
Disadvantages of VA ECMO

Ligation of the right carotid artery

Nonpulsatile arterial blood flow

Suboptimal conditions for LV function
 Low preload
 High afterload
 High wall stress
 Low coronary oxygenation
Disadvantages of VA ECMO

Systemic emboli
 Air
 thrombus
Advantages of VV ECMO

No ligation of carotid artery

Normal pulsatile blood flow

Optimize LV performance
 More preload
 Less afterload
 Better coronary oxygenation
 Less ventricular wall stress

No systemic emboli
Disadvantages of VV ECMO
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

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Need a functioning LV
Mixing of blood
lower arterial saturation
 Need increased ECMO flow
 Need higher hemoglobin
Need to place a larger cannula
More difficulty monitoring adequacy of
oxygen delivery
Recirculation of ECMO flow
Disadvantages of VV ECMO

May need to convert to VA

Need to be fully heparinized

Cannula cannot be heparin bonded
VV ECMO -Double lumen

Newborns
 >90% of VV ECMO - Double lumen
 12F and 15F OriGen

Pediatric
 35% of VV ECMO -double lumen
 18F - largest OriGen cannula
 65% internal jugular, femoral, sapphenous
VV ECMO -Double lumen

Cannula site

Internal jugular vein (15F double lumenpreferred)
 Cannula tip low in the right atrium
Drainage
Infusion
High lateral RA
Mid Medial RA
Low lateral RA
Endhole
Optimal Cannula Placement


Adequate size
Correct depth

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Correct Rotation
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Low Right Atrium
Label visible
Drainage limb (Blue) posterior
Infusion limb (Red) anterior
Vertical orientation
Head - midline
No Kinks
Recirculation

Oxygenated ECMO blood returning to
the ECMO circuit immediately after
infusion
Recirculation factors

Head /cannula position
 Changes with head rotation
 Changes in lung volume / relative position
of the heart and cannula

ECMO flow

Right atrial size / intravascular volume

RV contractility
ECMO blood flow
to baby - 160
ECMO Flow reads 200
ECMO blood flow
to baby - 250
ECMO Flow reads 500
ECMO Flow -Recirculation

More ECMO flow will always increase
recirculation

More ECMO flow may either


Increase blood flow to baby
Decrease blood flow to baby
VA ECMO

ECMO flow rate is proportional to the level of
support

More flow
More support
Always advantageous if more flow is possible
More ECMO flow will always increase SvO2


Pulmonary Support - VV

Net ECMO blood flow of infant = measure
ECMO flow - recirculation flow

ECMO flow (flow probe) DOES NOT indicate
level of support

SvO2 DOES NOT reflect level of systemic
oxygen delivery
Circulatory Support

Net flow to baby assessed by
 Infant color
 Infant arterial saturation and PaO2
Assessment of Recirculation

More recirculation if
 Decreasing baby arterial sat or PaO2
 Increasing SvO2 on ECMO circuit
 Decreasing color difference on drainage
and infusion limbs of circuit
Reducing Recirculation

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Adjusting relative cannula position
 Head position
 Lung inflation
Decrease ECMO flow
Increase intravascular volume
Increase RV contractility
 Volume
 Vasopressors
 Pulmonary vasodilators
VV - VA Conversion


Needed if
10-15% of cases


Hemodynamic support is inadequate
Respiratory support is inadequate

More problematic when ultrafiltration is used
VV ECMO - Specific Issues

ECMO Prime
Must have added heparin
 Must have Ca added
 Ionized Ca on circuit must be
checked prior to cannulation
 Potassium must be checked

Heparin

If no heparin added


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Addition of Ca binds citrate of blood
products
Loss of anticoagulant activity
Acute clotting of the entire circuit
Need to prime another circuit
Calcium

If no calcium added



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Acute hypocalcemia - Ca binds to citrate of
blood products
Loss of LV and RV contractility
Acute hypotension
Cardiac arrest
Potasium

If potassium in prime is not checked



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Possible higher serum K from the stored
PRBC
Acute hyperkalemia
Arrythmia
Cardiac arrest
Head / Cannula Position

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
Distal tip low in RA
Head in the midline with vertical orientation of
the drainage and infusion limbs
RA drainage ports


Lateral
Infusion ports

Medial
Keys to Management

VV ECMO- DL
 Need to think in terms of NET blood flow
to the baby
 Cannot quantify NET flow
 SvO2 is not indicative of adequacy of
systemic oxygen delivery
 Indirectly assessed with SaO2 and
PaO2 on the infant
To Improve oxygenation



Give PRBC
Increase ECMO flow
Decrease recirculation



Check cannula position
Increase ntravascular volume
Increase RV contractility
Rest Ventilator Settings


Pressures - similar to VA
FiO2 - able to wean to RA frequently

Better myocardial oxygenation via ECMO
flow than VA
Jugular venous drainage


11% of all double lumen VV
Small study suggested decrease IVH


Reduced cerebral venous pressure
Advantage
 Additional drainage facilities flow
 2 site venous drainage lessens
recirculation on VV ECMO
 Improved oxygen delivery
 Enables venous oxygen saturation
monitoring on VV ECMO
Jugular Venous Drainage
Cephalad Cannula
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J Pediatr Surg 2004;39:672-676
Review of ELSO database
Neonatal Respiratory Failure VV ECMO
1989-2001
N = 2471
 96% VV double lumem alone
 3.7% with jugular venous drainage
Similar Outcomes
Operating Parameters

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SaO2 - 85-95%
PaO2 40-65 torr
Blood pressure - similar to VA
ECMO flows - 130-150+ ml/kg/min
HgB 12-15 g/dl
Weaning of ECMO - VV


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No clamp out needed
Increase ventilator
Decrease sweep gas flow rate and FiO2
Sweep gas flow can be completely stopped
 SvO2 will reflect mixed venous saturation
 No recirculation
Gas
Flow
NO Gas
Flow
VV ECMO Outcomes

Generally slightly better than VA, but
slightly different patient populations



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Hemodynamically more stable
Less exposure to CPR
Better survival
Shorter duration of ECMO
Conversion VV to VA

12%
VA - VV Comparison studies



J Peds Surg1993;28:530-536
Multicenter data
N=243
 VA = 135
 VV = 108
 Similar survival
 10% conversion to VA
 Shorter runs
 Less Neurologic complications