ECMO for cardiac arrest patients: Update 2017 Lim Swee Han MBBS (NUS), FRCS Ed (A&E), FRCP (Edin), FAMS Senior Consultant, Department of Emergency Medicine, Singapore General Hospital Adjunct Associate Professor, Yong Loo Lin School of Medicine and Duke-NUS Graduate Medical School of National University of Singapore Treasurer and Member BLS Taskforce, ILCOR Chairman, Resusciation Council of Asia Secretary, Asian Society for Emergency Medicine President, Society of Emergency Medicine in Singapore
Acknowledgements Dr Lim Jia Hao Consultant Department of Emergency Medicine Singapore General Hospital Dr Tan Boon Kiat Kenneth Consultant Department of Emergency Medicine Singapore General Hospital
What is ECMO? The use of extracorporeal circulation and gas exchange to provide TEMPORARY life support in patients with REVERSIBLE pulmonary and/or cardiac failure.
History of ECMO Dimethylpolysiloxane (DMPS, silicone), was discovered in 1957, and by 1963, used in the construction of oxygenators It will pave the way for extracorporeal life support systems
First Successful ECLS Patient, 1971
1972-1975 First Cardiac ECMO Survivor, 1972 First Neonatal ECMO Survivor, 1975
ELSO Extracorporeal Life Support Organization Established 1989 Outgrowth of a study group contributing to a registry of cases starting in 1984 Surgeons, neonatologists, nurses, perfusionists, RTs, biomedical engineers Develops ECLS guidelines, textbooks, and maintains a registry
Types of ECMO Veno-arterial ECMO Used for refractory cardiogenic shock and for E CPR Veno-venous ECMO Usually used for respiratory failure refractory to other conventional treatments. Conditions like severe pneumonia, Pneumonitis
V-V ECMO Indications Adult Respiratory Distress Syndrome (ARDS) Pneumonia Trauma Graft failure following lung transplantation Paediatric and neonatal respiratory support E.g., HMD, MAS, PPHN, CDH etc Extensive research done in this patient population
V-A ECMO Severe cardiac failure Decompensated cardiomyopathies Myocarditis Acute coronary syndromes with cardiogenic shock Profound cardiac depression due to drug overdose or sepsis Post-cardiotomy or post-heart transplant Cardiac arrest (<15 min, with excellent CPR)
Increased Survival Adult ARDS survival up to 70% Paeds ARDS survival up to 75% For cardiogenic shock: Myocarditis 70% Decompensated CMP 50% Cardiogenic shock with ACS 40% In-hospital cardiac arrest 34% Out-of-hospital cardiac arrest 13%
ECLS vs CPB Feature CPB ECMO Duration Hours Days to Months Configuration VA bypass VA or VV Membrane Microporous Nanoporous Blood pump Roller Centrifugal Circuit volume Large Small Anticoagulation High Low Reservoir Large Small or absent Cannulation Central (RA to aorta) Peripheral Patient Anaesthetized, paralysed Awake, or sedated Management Perfusionist Nurse, Perfusionist, RT
ECMO Circuit About 15-30 min to prime a full circuit Lasts about 30 days
Components of Circuit (I) Access Cannula: Distal tip has multiple holes and a main central lumen; drains deoxygenated blood from venous system Return Cannula Single end lumen; returns oxygenated blood back to patient
Components of Circuit Centrifugal Pump Head Artificial heart that pushes the deoxygenatd blood into the oxygenator Pressure differential at inlet and outlet results in flow Oxygenator with integrated heat exhanger Artificial lung where gas exchange takes place Temperature regulation
Components of Circuit (II) Monitor displaying venous O2 saturation and HCT Pump console and drive motor to adjust flow Flow probes and flow sensors Circuit pressure monitors (pre-pump, post-pump) Heater/cooler unit with temperature display Frequent inspections for clots in circuit Watch for circuit chatter Minimize excessive connections e.g., stopcocks, tube connectors etc Minimize length CLAMPS and TORCHLIGHT readily available
ECMO Complications (I) Haemorrhage Embolism Leg ischaemia Infection Anticoagulation and resultant bleeding Balancing act between sufficient anticoagulation, and thrombosis Cerebrovascular infarct / bleed Pulmonary oedema Sepsis Increase in LV afterload
ECMO Complications (II) Non-pulsatile (if high flow VA ECMO) Altered physiology Harlequin syndrome flow competition in the aorta (native cardiac output, vs retrograde aortic perfusion from arterial cannula), if pulmonary function impaired, then: Blue head Red legs Always measure SpO2 and blood gases on R side
Extracorporeal membrane oxygenation support
In-hospital cardiac arrest Aged 18-75 who underwent CPR >10min Cardiac origin raised cardiac enzymes before CPR, sudden collapse without obvious causes, or with pre-existing cardiovascular disease Exclusion Criteria: Severe irreversible brain damage Terminal malignancy Traumatic origin with uncontrolled bleeding Non-cardiac arrest Previously signed Do not attempt resuscitation Chen, Lancet 2008, 554-61
In-hospital cardiac arrest Chen, Lancet 2008, 554-61
In-hospital cardiac arrest Chen, Lancet 2008, 554-61
ECRP vs CCPR in adults OHCA: A prospective observational study Inclusion criteria: 1. VF/VT initial ECG 2. Cardiac arrest on hospital arrival with or without pre-hospital ROSC 3. Within 45min from reception of the emergency call or onset of cardiac arrest to the hospital arrival 4. No ROSC at least during the 15min after hospital arrival (ROSC defined as at least 1min of continuing confirmation of pulsation) Exclusion criteria: 1. Under 20 years old, or 75 years and older 2. Poor level of activities of daily livings before onset of cardiac arrest 3. Non-cardiac origin (eg external factors such as trauma and drug intoxication, primary cerebral disorders, acute aortic dissection diagnosed prior to the introduction of PCPS, and terminal phase of cancer) 4. Core body temperature less than 30 C Sakamoto T Resuscitation 2014
Sakamoto T Resuscitation 2014
Patients with refractory OHCA were eligible for the study if aged 18-65 years cardiac arrest due to suspected cardiac aetiology chest compressions commenced within 10 mins by bystanders or EMS initial cardiac arrest rhythm of ventricular fibrillation (VF) mechanical CPR machine (Autopulse) available Patients with IHCA were eligible at the discretion of the attending critical care physician when it was considered likely that the cardiac arrest would be reversible if venoarterial ECMO and definitive treatment could be provided immediately. Patients with IHCA were excluded if they were known to have significant pre-existing neurological disability Non-cardiac co-morbidities that cause limitations in activities of daily living such as severe chronic airways disease, cirrhosis of the liver, renal failure on dialysis and terminal malignancy Patients with cardiac arrest and ROSC followed by cardiogenic shock who were later treated with veno-arterial ECMO are not included in this report Dion et al. Resuscitation 2015
Dion et al. Resuscitation 2015
A Bunch of Caveats: Patient selection is crucial Centers with high volume of ECMO patients demonstrate the best outcomes Scrutinize the evidence observational studies++, small numbers No randomized study data available for ECMO/ECLS use in cardiogenic shock
A Dash of Cold Water ECMO resuscitates the moribund it cannot reanimate the dead. It remains a non-durable technology ECLS itself is a relatively simple procedure, however, the management paradigms are complex ECLS accomplishes nothing (non-therapeutic), but facilitates EVERYTHING It can support patients awaiting good clinical decision making it is ineffective in supporting bad clinical decisions It truly is a bridge
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