Management of Infants
requiring ECMO
Sixto F. Guiang, III
Dept. of Pediatrics
University of Minnesota
Extracorporeal membrane
oxygenation- ECMO

Mode of cardiopulmonary support
 Pulmonary failure
 Cardiovascular insufficiency

Adapted from cardiopulmonary bypass done
in OR

Infants, children, and adults
Neonatal ECMO = 73 % of all ECMO
VV ECMO = 20% of all Neonatal Pulmonary
Recent ECMO





Pediatrics 2000;106:1334-1338
Fewer patients
Longer ECMO runs
Longer time prior to ECMO
Higher mortality
Extracorporeal Life Support
Organization: ELSO



Develop guidelines for use
Quality assurance
Education



Text
Regulatory issues
Database
 Clinical needs
 Research needs
 www.elso.med.umich.edu/
Inclusion ECMO Criteria


Gestational age of at least 34 weeks
Weight >1.7-2.0 kg
Inclusion / Exclusion
Guidelines








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
Reversible Lung Disease

No prospectively defined criteria have been
developed

Pre-ECMO gas exchange is not predictive of
baseline lung capability

ECMO utilized in

Lung hypoplasia



Congenital diaphragmatic hernia
Renal anomalies
Hydrops fetalis
Oxygenation Failure

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

paO2



PaO2 < 35 for 2 hours
paO2 < 50 for 12 hours
Acute decompensation

paO2 < 30 torr
Myocardial Failure

Refractory hypotension

Low cardiac output

pH <7.25 for 2 hours or greater

Uncontrolled metabolic acidosis secondary to
hemodynamic insufficiency

Cardiac arrest - CPR
Predicted / Measured
Outcomes

Historical Mortality
80%

Mortality RCT- conventional tx
50%

ECMO mortality
15-25%
Arterial Cannula
Oxygenator
Pump
Venous Cannula
Gas
Flow
Gas
Flow
Gas Exchange - Oxygenator
100% FiO2
pO2 - lower
pCo2 - higher
Gas permeable surface
pO2 - 32
Oyxgen saturation 70%
pCO2 - 45
Blood flow
pO2 - 700+
pCo2 - 0
pO2 – 450+
Oyxgen saturation 100%
pCO2 - 40
Gas Exchange

Gas flow rate (sweep gas flow)


Determines CO2 removal
Gas Flow FiO2


Small effects on infant oxygen saturation
Changes paO2 of ECMO output only
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
Pre ECMO Evaluation

ABG, electrolytes, Ionized Ca++

Cardiac echo
 Evaluate pulmonary artery pressures
 Evaluate right and left ventricular function
 Rule out cyanotic congenital heart disease
Unsuspected Heart disease

2% of all ECMO for presumed respiratory
disorders



33.5% were TAPVR
10.5% Transposition of the great arteries
7.5% Ebstein’s Anomaly
Pre ECMO Evaluation

Head US
 Rule out severe IVH

Coagulation studies
 INR, PTT, TT, fibrinogen, platelets
ECMO Goals

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
Adequacy of Support - SvO2
Aorta
Right Atrium
70%
Oxygen consumption
Tissue
Vein
Artery
100%
Post
Pre
ABG
Adequacy of Support

Tissue oxygenation
 Not the same as arterial oxygenation
 Oxygen Delivery
 Oxygen content Blood
 Arterial oxygen saturation
 Hemoblobin
 Blood flow
 ECMO
 cardiac
Adequacy of Support - SvO2
Ao
Vena cava
70%
Oxygen consumption
Tissue
85%
Adequacy of Support - SvO2
Ao
Vena cava
55%
If Oxygen
inadequate
oxygen delivery
consumption
Anerobic metabolism
Tissue
Lactic
adidosis
100%
SvO2

Generally good indicator of adequacy of
oxygen delivery

SvO2 will drop with decreasing tissue oxygen
delivery
Low SvO2
 More support is needed
 PRBC
 More flow
 ECMO

Adequacy of Support - SvO2
Ao
Vena cava
55%
Oxygen consumption
Tissue
100%
SVC
Brain
Upper extremities
Right Atrium
SvO2
Heart
Kidney
IVC
Intestines
Liver
SvO2 - Problems


Cannot be used with VV ECMO
because of recirculation
Affected by intracardiac shunt



Patent foramen ovale
Gives a macro picture of oxygen supply
and demand
Ignores potential differences in regional
(organ) blood flow
SvO2 - Alternatives

Tissue oxygen saturation via near
infrared spectroscopy (NIRS)




Transcutaneous measurement
Detection of blood saturation in the tissues
Primarily venous blood sampled
Can be used as a indicator of organ
specific venous oxygen saturation
VA ECMO

Cannula sites

Internal jugular vein
(12-10F)
 Cannula tip low in the right atrium

Right common carotid artery (10-8 F)
 Cannula tip at the aortic arch
Cannulation

Preparation
 Remote vascular access
 Extension tubing on central venous
catheter and arterial catheter
 Accessible easily away from the sterile
surgical field
Medications






Fentanyl 25-30 micrograms/kg
Atropine 0.01 mg/kg
Neuromuscular blocking agent
Heparin 100 units/kg bolus
 Needed even if continuous heparin gtt will
not be used
Ca
Volume
 NS, PRBC, FFP, Albumin
 Prime oxygenated circuit blood
Arterial Cannula
Venous Cannula
Carotid
ECMO
PDA
PA
Ao
PA
LV
RV
Ao
Ventricles
Po2 - 45
Sat - 88%
ECMO
Po2 - 450
Sat - 100%
Po2 - 150
Sat - 100%
Ventricles
ECMO
Po2 - 450
Sat - 100%
Po2 - 450
Sat - 100%
Ventricles
Po2 - 32
Sat - 70%
ECMO
Po2 - 150
Sat - 100%
Ventricles
Po2 - 32
Sat - 70%
ECMO
Po2 - 150
Sat - 100%
Po2 - 70
Sat - 97%
Ventricles
Po2 - 32
Sat - 70%
ECMO
Po2 - 150
Sat - 100%
Po2 - 50
Sat - 88%
Management




Fluids / Nutrition
Respiratory
Hemodynamic
Anticoagulation
Fluids / Nutrition

Obligate need to maintain intravascular
volume
 90-100+ ml /kg/day
 Exacerbated by capillary leak and 3rd
spacing of fluid
 Activation of cytokines / complement /
leukocytes
 Vasodilatation
 Increased vascular permeability
Na

Generally total body sodium overloaded
 Volume expansion with NS
 Blood products
 Delayed Na increases with PRBC
 Na/k ATPase pump turned off
 High intracellular Na
Potassium

Potential problems with Hyperkalemia
 Hemolysis
 Circuit
 Stored blood
 High serum K in PRBC bag
 Na/K ATPase pump inactivated
 Hemodynamically significant only in VV
ECMO
Calcium

Hypocalcemia




Low ionozed Ca
Normal total Ca
Ca binding to citrate from blood
products
Standing order for Ca Gluconate after
100 ml colloid infusion
Energy Delivery

Non protein calories
 50-60 kcals/kg/day
 Carbohydrate
 Fat

No direct studies suggesting ideal mix
Lipid infusions

Technical problems relating to the ECMO circuit
 Promoting clot formation
 Layering out of the emulsion
 Fat deposition
Avoid Excessive Calories
Rate of
Appearance
Of CO2
J Ped Surg 1999; 34:1086-1090
Avoid Excessive Calories
J Ped Surg 1999; 34:1086-1090
High Caloric intake

Increasing caloric intake associated with:
 Increased amino acid oxidation
(r=0.85, p<.001)
 Increased protein breakdown
(r=0.66, p<.05)
 Trend towards longer ECMO time (r=0.54, p=.07)
Pulmonary Management

Aim to control pH and paCO2 only with
the ECMO circuit

Changes in sweep gas Flow Rate will
increase CO2 removal
Pulmonary Management



Maintain lung aeration
 PEEP
12-16
If lung disease
 PEEP
6-8
If no lung disease
 Early Surfactant replacement
Minimize ongoing lung injury - VILI
 Pressure preset vent PIP - 20, RR - 10
 PIP adjusted for recruitment
 HFOV
Provide adequate myocardial oxygenation

FIO2 40%
Carotid
ECMO
PDA
PA
Ao
PA
LV
RV
Ao
Rest ventilator settings

PEEP Maintaining FRC probably a
good lung protective strategy


Pediatrics 1992;120:107-13
Randomized clinical trial
 N = 74
 High PEEP = 12-14
 Low PEEP = 3-5
Rest ventilator settings


Similar survival
High PEEP
 Higher (better) CXR scores
 Shorter ECMO run
 97.4 vs 131.8
hours
PEEP
Surfactant

Alteration of surfactant metabolism

Decreased SP-A levels in tracheal
aspirates in ECMO patients

Increased surfactant proteins and
phospholipids in correlate with
improvement in lung function
Surfactant Replacement



J Peds 1993;122:261-268
Randomized, blinded trial
N=56
 Survanta
4 doses
 Placebo
 Dosing at 2, 8, 20 and 32 hours
Surfactant Replacement

In surfactant group





Faster improvement in compliance
Faster increase in SP-A
No difference in CXR scores
Shorter ECMO runs
Surfactant not beneficial for CDH
Time course

Dependant on disease process

Meconium aspiration
3-5 days

Congenital diaphragmatic hernia 7-14 days

Lung hypoplasia syndromes 14+ days
Cardiovascular Instability


Hypotension
Hypertension
Pressure = Flow x Resistance
Ventricles
ECMO
Hypotension

Volume -If intravascular volume depletion



Ca


Increase blood drainage to the ECMO pump
Increase preload to LV/RV
Myocardial contractility
Vasopressors


Increase systemic vascular resistance (SVR)
Increase LV and RV
Anticoagulation


Systemic heparin
Bolus heparin at cannulation


Continuous heparin gtt



100 units/kg
20-50 units/kg/hour
Procoagulants factors
Anticoagulant factors
Operating Parameters

Gas Exchange





pCO2 35-45
pH 7.35-7.45
SvO2 > 70%
PaO2 50-100
SaO2 >90%
Operating Parameters

Hemodynamics


Capillary refill time - 2 seconds
Evidence of adequate organ perfusion



Urine output
No metabolic acidosis
BP- dependant on gestational age


SPB > 60
Mean BP > 45-50
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
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
Operating Parameters

ECMO




Flow 10O-120+ ml/kg/min
HgB 10-12
Platelets >100K
Anticoagulation


Variable
When fully anticoagulated

ACT 180-220 seconds
ECMO outcomes

Mostly determined by




Dx
ECMO duration
Hospital course
IVH
Jugular venous drainage

Additional drainage facilities flow

2 site venous drainage lessens recirculation
on VV ECMO

Enables venous oxygen saturation monitoring
on VV ECMO

One small study suggested decreased IVH
Jugular Venous Drainage
Cephalad Cannula





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
Complications - Infants






IVH
Other Bleeding
Hemolysis
Ultrafiltraltion/dialysis
Acute Renal failure
Arrhythmia
10%
15%
15%
13%
10%
3%
IVH



Most serious long term complication
Highest Risk period 1-5 days
Risks
 J Peds 1999;134:156-159
 ELSO database
 N=3896
 9.8% ICH
 30% cause of death
Increased Risk of IVH
< 34 wks
34-36 wks
36-38
Epinephrine
Sepsis
pH <7.0 (last)
pH 7.0-7.2
Coagulopathy
OR
12.1
4.1
2.1
1.9
1.8
2.5
1.8
1.6
CI
6.6-22.0
2.9-5.8
1.6-2.8
1.5-2.5
1.4-2.4
1.6-3.9
1.1-2.2
1.1-2.2
IVH

No difference in







Apgar
Fetal distress
IUGR
Pneumothorax
Pulmonary hemorrhage
VV ECMO
Jugular venous drainage
IVH - Lactate




Pediatrics 1995;96:914-917
Initial
10 vs 6.4
Maximal 12.4 7.9
Predicted ICH logistic regression
 None <2.5
 20% at lactate >10
 40% at lactate >25
 60% at lactate >40
Lactate as Predictor of
Outcome






CCM 2002;30:2135-2139
Prospective trial
2 centers
N=74
20% Early mortality
9% additional infants died before 18 mo
follow up
Lactate

Peak lactate >25 predicted early
mortality




Sensitivity
Specificity
Positive predictive value
Negative predictive value
47%
100%
100%
88%
Lactate

Peak lactate >15 predicted adverse
outcome




Sensitivity
Specificity
PPV
NPV
35%
91%
89%
38%
Time to Give up?

Best estimate based on long runs of
congenital diaphragmatic hernia

Low additional survival past 21 days
PROPORTION OF INFANTS REMAINING ON ECMO WITH SUCCESSIVE DAYS
1.00
.90
P
E
R
C
E
N
T
.80
.70
.60
SURVIVORS
NON-SURVIVORS
.50
.40
.30
.20
.10
0.00
0
10
20
30
DAYS ON ECMO
40
50
60
Daily Specific Survival Rate
Second ECMO


J Peds Surg 2002;37:845-850
ELSO database





N=16,450
Second
1.22%
Third
4 infants
More complicated during second run
Survival
38%

MAS still >85% survival
Early ECMO



J Peds Surg 2002;37:7-10
Meconium Aspiration
ELSO database



N=3235
Overall mortality 5.8%
Increased mortality with increasing time to
ECMO
Mortality - MAS
9
8
7
6
5
Mortality
4
3
2
1
0
<24 hours
1-4 days
> 4 days
ECMO Duration - MAS
500
450
400
350
300
250
200
150
100
50
0
Hours
<24 hours
1-4 days
> 4 days
Weaning of ECMO

Assess pulmonary status
 Compliance
 Vt with set Pmax, PEEP
 Typical maximal vent setting
 Pmax 30
 RR 35-40
 FiO2 50%
 HFOV
 Pulmonary hypertension
 Cardiac echo
 pre-post ductal saturations
Recovery and Decannulation

Adequate gas exchange





PIP <30
PEEP<7
Rate <35-40
FiO2<50%
Adequate cardiac output and BP

Cardiac echo
Weaning of ECMO

Assess hemodynamics



Ventricular funcion
Organ perfusion
BP
Weaning of ECMO - VA


ECMO flows weaned
Minimum ECMO flow 100 ml/min



Risk for clot formation inceases with lower flows
(absolute flow rate)
Frequent assessment of activated clotting time
(ACT) is needed
Ventilator settings at maximum Pmax to give
desired Vt



Assessment of gas exchange via SaO2 and ABG
Additional preload frequently needed
Additional Ca
VA ECMO Clamp Out



Cannula - clamped
Bridge - Opened
Stagnant blood
 Tubing and cannula distal to the bridge
 Intermittent flow in the cannula needed
every 5-10 minutes
Future Management Issues



Hypothermia
Extracorporeal CPR
Follow up


High incidence of late hearing loss
Routine late screening recommended
ECPR - Extraporporeal
Cardioulmonary Resuscitation


CPR is not a contraindication for ECMO
End organ perfusion may be better post
CPR in infants treated with ECMO
Pediatr Crit Care Med 2004;5:440-446
Case VA ECMO for Sepsis



Infants ABG
Post oxygenator
Preoxygenator



7.34 / 40 / 350 / 19
7.34 / 40 / 450 / 19
7.30 / 46 / 20 / 19
CXR - “White out”
Systemic oxygen delivery is:
 Low - pvO2 is low, SvO2 is low
Cardiac output is:
 Low - paO2 in infant is similar to the post
oxygenator paO2
Case VA ECMO for Sepsis



Infants ABG
7.36 / 40 / 52 / 24
Post oxygenator
7.39 / 36 / 450 / 24
Preoxygenator
7.30 / 44 / 40 / 24
 Systemic oxygen delivery is:
 High - PvO2 is high, SvO2 is high
 Cardiac output is:
 Good - large gradient between infant ABG and
post oxygenator gas
 Mixing of LV and ECMO output