Fellow`s Conference: Medical management of Neonatal ECMO
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Transcript Fellow`s Conference: Medical management of Neonatal ECMO
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