CHAIRPERSON : DR.YASHODHA.H.T. PRESENTER : DR.ASHA NIVEDITA.N. Extra Corporeal Membrane Oxygenation - ECMO 1
CHAIRPERSON : DR.YASHODHA.H.T.
PRESENTER : DR.ASHA NIVEDITA.N.
Extra Corporeal Membrane Oxygenation - ECMO
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REFERENCES
ASSISTED VENTILATION IN NEONATE – FOURTH EDITION- GOLDSMITH
NELSON TEXTBOOK OF PAEDIATRICS – 18TH EDITION
MANUAL OF NEONATAL CARE – JOHN.P.CLOHERTY
RECENT ADVANCES IN PEDIATRICS – 10TH EDITION - DAVID
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History
Dr. John H. Gibbon JrECMO originates from the first blood
oxygenator developed in the 1950‘s - In 1930 he started working on techniques
for extracorporeal circulation after a patient
died from pulmonary hemorrhage. The first interest was thus pulmonary support and not cardiac
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Contd.
The first oxygenators sustained blood – air interventionVarious complications and organ deteriorations after limited time. Experiments showed the negative effects of blood-air interface The next goal was to develop the membrane oygenator Clowes build the first membrane oxygenator using polyethylene 1956 this device was successfully applied in cardiac
surgery
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Improved membrane oxygenators
Kammermeyer discovered that dimethylpolysiloxane membranes allowed much better diffusion rates than polyethylene.
This became the membrane of choice and the improved diffusion rates of this membrane made extended life support possible.
- Bleeding was still a problem, and the numerous transfusion that would be needed for extended support made the therapy unfeasible.
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Robert Bartlett team in the mid-1960‘s showed that longer support times was possible by reducing the heparin dosage.
1972 a patient was successfully supported by use of membrane oxygenation for 3 days.
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The 70‘s urged for a device that could provide extended heart-lung bypass.
Extracorporeal oxygenation – well suited to allow healing time in respiratory failure. In 1975, both the NIH and the lung Division of
the Heart and Lung Institute began a study on ECMO.
In the same year the first newborn infant was successfully sustained using ECMO under the care of
Dr.Bartlett
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Whenever we think of ECMO, we think8
INTRODUCTION
ECMO is instituted for the management of life threatening pulmonary or cardiac failure (or both), when no other form of treatment has been or is likely to be successful.
ECMO is essentially a modification of the cardiopulmonary bypass circuit which is used routinely in cardiac surgery.
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Instituted in an emergency or urgent situation after failure of other treatment modalities.
It is used as temporary support, usually awaiting recovery of organs
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Dynamics of ECMO
Blood is removed from the venous system either peripherally via cannulation of a femoral vein or centrally via cannulation of the right atrium, Oxygenate Extract carbon dioxide
Blood is then returned back to the body either peripherally via a femoral artery or centrally via the ascending aorta.
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ECMO SELECTION CRITERIA
AaDO2 > 610 x 8 hrs or 605 x 4 hrs, if PIP >38cm H2O
Oxygen index > 40Acute Deterioration with PaO2 <40 x2hrs and/or
pH<7.15 x 2hrsUnresponsive to treatment PaO2<55 & pH <7.4
x3 hrsBarotrauma – pneumothorax, pneumopericardium,
pneumoperitoneum, pulmonary interstitial emphysema, persistent air leak >24 hrs
MAP >15cm H2O and subcutaneous emphysema
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Indications for ECMO
Divided into two type
Cardiac Failure
Respiratory Failure
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Absolute contraindications16
Lack of parental consentInadequate conventional therapyWeight <2000gGestational age <35 weeksContraindication to anticoagulation – severe
pulmonary hemorrhage IVH , gastrointestinal hemorrhage, head
trauma,prolonged mechanical ventilation > 7-14 days
- History of severe asphyxia
Relative contraindications
Prolonged severe hypoxiaProlonged mechanical ventilation >7 daysStructural cardiac disease History or evidence of ischemic neurologic
damage
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Configurations for ECMO
ECMO can be inserted in 2 configurations:
Veno-venous
Veno-arterial
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Veno-arterial (VA) configuration Blood being drained from the venous system and
returned to the arterial system. Provides both cardiac and respiratory support. Achieved by either peripheral or central cannulation
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Veno-arterial20
Veno-Venous (VV) configuration Provides oxygenation Blood being drained from venous system and returned
to venous system. Only provides respiratory support Achieved by peripheral cannulation, usually of both
femoral veins.
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Comparison of V-V & V-A ECMO22
V-V ECMO
V-A ECMO
ADVANTAGES Requires venous access only Good oxygenation and CO2
removal
Pulsatile flow to organs preserved via native cardiac function in series with ECMO circuit
ECMO circuit both in parallel and in series with native cardiopulmonary circuit. The fraction of blood flowing in parallel is dependant upon the ECMO pump velocity
Good CO2 removal Can provide partial cardiac bypass and cardiac rest
Easy to wean off from ECMO support
Rapid wean of ventilator, inotropes and pressors
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DISADVANTAGES
V-V ECMO V-A ECMO
Dependance on native cardiac function for cardiac output
Non-pulsatile flow
Decreased oxygen delivery to periphery compared to V-A ECMO
Cannulation of right carotid artery
Decreasedflow if mediastinum is displaced
More difficult to wean off from ECMO circuit
Mechanical ventilation must be continued during ECMO support to try to maintain oxygen saturation of blood ejected from the left ventricle to at least above 90%.
ECMO flow can be very volume dependent
ECMO flow will drop: Hypovolemia Cannula malposition Pneumothorax Pericardial tamponade.
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Arterial pressure waveform
Wide pulse pressure correlates with low ECMO flow
Narrow pulse pressure correlates with high ECMO flow
Mean pressure is most important
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Weaning from ECMO – VA ECMO
Depends on cardiac recovery, Factors: Increasing blood pressure Return or increasing pulsatility on the arterial pressure
waveform Falling pO2 by a right radial arterial line
indicating more blood is being pumped through the heart which may be less well oxygenated,
Falling central venous and/or pulmonary pressures.
It is important to note that cardiac outputs from pulmonary artery catheter are inaccurate on ECMO Most of the circulating blood volume is bypassing the
pulmonary circulation
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Complications
Falls into one of three major categories
1) Bleeding associated with heparinization2) technical failure3) neurologic sequelae
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Complications of ECMO
Bleeding/Hemolysis Out of proportion to the degree of coagulopathy
and patient platelet count
Coagulopathy Continuous activation of contact and fibrinolytic
systems by the circuit Consumption and dilution of factors within minutes of
initiation of ECMO
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Thrombocytopenia Platelets adhere to surface fibrinogen and are activated Resultant platelet aggregation and clumping causes
numbers to drop
Non-pulsatile perfusion to end organs Kidneys Splanchnic circulation seems to be particularly
susceptible GI bleeding, ulceration and perforation Liver impairment
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Complications (contd.)
Mechanical Complications Tubing rupture Pump malfunction Cannula related problems
Local complications: Leg ischemia Particularly at peripheral insertion site of VA
Air embolism/ThromboembolismNeurological: Intracerebral bleeds
Largely associated with sepsis Manifest as seizures or brain death
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Management of complications
Regular measurements of blood tests (Q6-Q8h) Coagulation Profile Platelet Count Hemoglobin Creatinine to evaluate for renal insufficiency
Aggressive replacement of clotting factors, electrolytes, PRBC
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