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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 88% MAS 98%
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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 88% • MAS 98% • CDH 68% • Others 84-93% • 90% veno-venous • 9% IVH
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 83% • Venoarterial 17% • Unable to place VV 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 FailureCriteria - 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 FailureCriteria - 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 • 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
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 • 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 lumen- preferred) • 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 • Low Right Atrium • Correct Rotation • 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 • 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 • 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 • 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 • Possible higher serum K from the stored PRBC • Acute hyperkalemia • Arrythmia • Cardiac arrest