ECMO - extracorporeal membrane oxygenation

ECMO

1. EXTRACORPOREAL MEMBRANE OXYGENATION (ECMO) - Dr. PRAPULLA CHANDRA D

2. INTRODUCTION HISTORY PRINCIPLE CIRCUIT & COMPONENTS INDICATIONS CONTRAINDICATIONS ECMO MECHANISM COMPLICATIONS OUTCOMES OF ECMO EXTRA CORPOREAL CO2 REMOVAL EXTRA CORPOREAL CPR

3. INTRODUCTION A form of extracorporeal life support where an external artificial circuit carries venous blood from the patient to a gas exchange device (oxygenator) where blood becomes enriched with oxygen and has carbon dioxide removed. The blood is then returned to the patient via a central vein or an artery. SOURCE : ECMO guidelines AlfredHealth Update nov 2015

4. HISTORY

5. 5 5 History of Extracorporeal Life Support 1950s Development of membrane oxygenator in laboratory 1971 First successful case 1972 First successful paediatric cardiac case 1975 First neonatal case (Esperanza) 1975-89 Trial in ARDS , 10% survival 1990 Standard practice for neonates and paediatrics in some centres 2000 Standard practice for adults in some centres 2009 Publication of the CESAR trial which led to a significant growth in the use of ECMO for ARDS cases

6. First successful ECMO patient in 1971 Figure 3.4. The first successful extracorporeal life support patient, treated by J. Donald Hill using the Bramson oxygenator (foreground), Santa Barbara, 1971.

7. First Neonatal ECMO survivor ..

8. FROM THIS TO THIS

9. ECMO PRINCIPLE Desaturated blood is drained via a venous cannula CO 2 is removed, O 2 added through an “ extracorporeal ” device The blood is then returned to systemic circulation via another vein (VV ECMO) or artery (VA ECMO).

10. ECMO serves as a BRIDGING THERAPY and not a curative therapy. Used as a -bridge to recovery :– i.e., buying time for patient to recover -bridge to decision :- provide temporary support to patient and allow clinicians to decide on the next step. -bridge to transplant :- provide support to patient while awaiting suitable donor organ.

11. ECMO CIRCUIT & COMPONENTS The basic components of ECMO circuit includes - a blood pump - membrane oxygenator & heat exchanger -controller -cannulas - tubings

12. PUMPS : They are basically of 3 types. - Roller pump - Impellar pump - centrifugal pump

13. CENTRIFUGAL PUMPS : Roller pumps are now being replaced by centrifugal pumps. The perfusion pressure is controlled by RPM (0-4000 RPM) Can deliver flow upto 8 L/min Very reliable upto 21 days.

14. Membrane Oxygenator : ECMO circuits have a gas exchange device called oxygenator, to add Oxygen and remove CO2 from blood.

15. Previously, silicon membrane oxygenators were used which are being replaced by Hollow fibre PMP( polymethyl pentene) membrane oxygenators. These are extremely efficient at gas exchange and demonstrate minimal plasma leakage, low resistance to blood flow.

16. GAS EXCHANGE : OXYGEN exchange depends on : Type of membrane & diffusion characteristics Thickness of the blood pathway Surface area of the membrane FiO2 in the gas phase Rate of blood flow CO2 exchange depends on : Difference in CO2 conc. b etween blood and gas Size of membrane Fresh gas flow Blood pathway thickness Blood flow rate

17. HEAT EXCHANGER : In adults, it is usually built within the oxygenator. In paediatric cases, it is connected separately after the oxygenator in the circuit. It is used for temperature regulation of the extracorporeal blood.

18. Controller panel for pressure monitoring and blood gas moitoring

19. TUBINGS : Depending on the heparin coating, they are of 2 types : - regular - heparin coated

20. 25 25 Different CONFIGURATIONS in ECMO Most common configurations: Veno -Venous ECMO (VV-ECMO): Used to support patients with severe respiratory failure refractory to conventional therapies Blood is drawn from a central vein , pass through an ECMO machine and then returned back via a central vein Veno -Arterial ECMO (VA-ECMO): Used to support patients with severe cardiac failure (with or without respiratory failure) Blood is drawn from a central vein , pass through an ECMO machine and then returned back via a central artery ECMO guidelines AlfredHealth Update nov 2015

21. Arterio -Venous ECMO (AV ECMO) : An arteriovenous (AV) extracorporeal circuit that uses the patient’s own arterial pressure or incorporates a pump to drive blood across an oxygenator can partially support the respiratory system by effectively removing carbon dioxide (CO2) (extracorporeal CO2 removal [ECCO2R ]). ECMO guidelines AlfredHealth Update nov 2015

22. VENO-VENOUS ECMO (VV ECMO) Venous blood is accessed from large central veins, pumped through the oxygenator and returned to the venous system near right atrium. There are 4 configurations of VV-ECMO depending on the cannulation sites. a) Femoro -femoral b) high flow c) femoro -jugular d) double lumen single canula (Avalon ) ECMO guidelines AlfredHealth Update nov 2015

23. Femoro -Femoral : Access cannula is inserted via the femoral vein with the tip sited within the ivc . Return cannula is inserted via contralateral femoral .v with the tip in right atrium. Advantages : quick and safe to insert, easy to secure cannulae . Disadvantages : limited maximum flow rates, often requires conversion to a high flow configuration.

24. High Flow : Uses the same bi-femoral cannulation . An additional short access cannula is inserted via the right internal jugular vein with tip in svc. Advantages : allows higher circuit blood flows as they draw blood from the great veins (svc & ivc ). -It is required in severe cases of respiratory failure when single access canula circuit flow is inadequate to maintain sufficient levels of gas exchange.

25. Disadvantages : -occupies 3 veins. - relatively complex to secure and dress the jugular cannula. - patient remains bed bound. - potential source of air embolism and pressure injury . ECMO guidelines AlfredHealth Update nov 2015

26. Femoro -Jugular : Access cannula – via femoral vein with tip sited just below the inferior cavo -atrial junction. Return cannula – into right internal jugular vein with the tip in lower svc. Advantage s : nearly can provide adequate support (5-7 l/min).

27. Disadvantages : - relatively complex to secure and dress the jugular cannula. - requires two sterile fields to be done during ECMO cannulation . - access insufficiency can be more difficult to identify in early stages without negative pressure monitoring . ECMO guidelines AlfredHealth Update nov 2015

28. Double lumen/Two stage single cannula ( Avalon ) : Single cannula with two lumens for access and return inserted via the right internal jugular vein. Advantages : single vein cannulation . Allows movement from bed and ambulation. Disadvantages : care on insertion to avoid right ventricular placement/rupture. Difficult to position return port towards the tricuspid valve.

29. VENO-ARTERIAL ECMO (VA-ECMO) Venous blood is accessed from the large central veins, pumped through oxygenator and returned to the systemic arterial system in the aorta. It provides support for severe cardiac failure with or without associated respiratory failure. Different configurations of VA ECMO are : -standard Femoro -Femoral -emergency Femoro -Femoral -High Flow -Central : specialised cannula -Central : Bypass cannula

30. Standard Femoro -Femoral : Access cannula is inserted via femoral vein with tip in right atrium. Return cannula : via common femoral artery with tip lying in common iliac artery or lower aorta. Advantages : provides full or partial cardiac support. Disadvantages : risk of differential hypoxia – may need conversion to high flow configuration if native cardiac function improves in the setting of significant respiratory failure.

31. Emergency Femoro -Femoral : Similar to standard femoro -femoral but uses SMALLER cannula which are quicker to insert in an emergency. Standard cannula : 21-25 Fr Emergency cannula : 19-21 Fr Advantages : faster to insert. Used for ECMO-CPR or in peri -arrest patients. Disadvantages : risk of differential hypoxia . ECMO guidelines AlfredHealth Update nov 2015

32. High Flow : Uses the same bi-femoral cannulation with additional access cannula inserted via the right internal jugular vein with tip in svc. Advantages : used to minimise differential hypoxia when native cardiac function improves.

33. INDICATIONS OF ECMO ELSO GUIDELINES : -Acute severe cardiac failure or respiratory failure with high mortality risk and reversible and non-responsive to optimal conventional therapy. -ECLS is considered at 50% mortality risk and indicated at 80% risk. SOURCE : ELSO General Guidelines Version 1.3 December 2013 ELSO- EXTRA CORPOREAL LIFE SUPPORT ORGANIZATION

34. ELSO GUIDELINES FOR ADULT RESPIRATORY FAILURE INCLUSION CRITERIA : 1. In hypoxic resp failure due to any cause (primary or secondary) a) 50% mortality risk associated with a PaO2/FiO2 < 150 on FiO2 >90% and Murray score 2-3 b) 80% mortality risk is associated with a PaO2/FiO2 <100 on FiO2 >90% and Murray score 3-4 despite optimal care for 6 hrs or more. 2. CO2 retention on Mechanical Ventilation despite high Pplat (>30cm H2O) SOURCE : ELSO General Guidelines Version 1.3 December 2013

35. 3. Need for intubation in a patient on lung transplant list 4 . Immediate cardiac or respiratory collapse (Pulmonary Embolism, blocked airway) unresponsive to optimal care. SOURCE : ELSO General Guidelines Version 1.3 December 2013

36. Parameter / Score 1 2 3 4 PaO 2 /FiO 2 (On 100% Oxygen) ≥300mmHg ≥40kPa 225-299 30-40 175-224 23-30 100-174 13-23 <100 <13 CXR normal 1 point per quadrant infiltrated PEEP(cmH 2 O) ≤5 6-8 9-11 12-14 ≥15 Compliance (ml/cmH 2 O) ≥80 60-79 40-59 20-39 ≤19 ECMO inclusion criteria - Murray score = average score of all 4 parameters

37. INDICATIONS : Reversible Respiratory Failure : ARDS Severe Pneumonias Severe Acute Asthma Chemical and Inhalation hypersensitivity Pneumonitis Near Drowning Post traumatic Lung Contusion Bronchiolitis Obliterans Autoimmune lung diease - Vasculitis , Good Pasture Syndrome SOURCE : ELSO General Guidelines Version 1.3 December 2013

38. Irreversible or Chronic Respiratory Failure : It is indicated as a bridge, only when- -patient is for lung assist device. Eg : PAL ( paracorporeal artificial Lung) -patient is waiting for lung transplant. SOURCE : ELSO General Guidelines Version 1.3 December 2013

39. CONTRAINDICATIONS : No absolute contraindications to ECLS in respiratory failure . Relative contraindications due to poor outcome are : - Mechanical Ventilation at high settings ( FiO2 >90%, P-plat >30) for 7 days or more. - Major pharmacological immunosuppression (absolute neutrophil count < 400/mm3) - CNS haemorrhage which is recent or expanding - Non recoverable co-morbidity such as major CNS damage or terminal Malignancy -Age : no specific age contraindication but increasing risk with age SOURCE : ELSO General Guidelines Version 1.3 December 2013 .

40. ELSO GUIDELINES FOR CARDIAC FAILURE : Cardiogenic shock -inadequate tissue perfusion manifested as hypotension and low cardiac output despite adequate intravascular volume. -shock persists despite volume administration, ionotropes and vasoconstrictors and intraaortic balloon counterpulsation if appropriate. SOURCE : ELSO General Guidelines Version 1.3 December 2013

41. typical causes : - Acute myocardial infarction -Myocarditis -Decompensated chronic cardiac failure -Post cardiotomy shock - Peripartum cardiomyopathy Septic shock SOURCE : ELSO General Guidelines Version 1.3 December 2013

42. ECMO advantages in cardiac failure : -Biventricular support, Bedside immediate application and oxygenation in Biventricular failure, Refractory malignant arrhythymias , heart failure with severe respiratory failure. ECMO is a Bridge to Recovery : Acute MI after revascularisation, Myocarditis, Postcardiotomy Transplant : Unrevascularizable acute MI, Chronic heart failure Implantable circulatory support : VAD SOURCE : ELSO General Guidelines Version 1.3 December 2013

43. CONTRAINDICATIONS ABSOLUTE : -Unrecoverable heart & not a candidate for transplant /VAD -Chronic organ dysfunction (Emphysema, cirrhosis, renal failure) -Prolonged CPR without adequate tissue perfusion RELATIVE : -Anticoagulation -Obesity -Advanced age SOURCE : ELSO General Guidelines Version 1.3 December 2013

44. ECMO MECHANISM It includes : -INITIATION -MAINTENANCE -DISCONTINUATION

45. INITIATION Once it has been decided to initiate ECMO, the patient is anticoagulated with i /v heparin and cannulae are inserted according to the ECMO configuration ( VV or VA ECMO) Following cannulation , patient is connected to ECMO circuit, the pump started with the flow of 20 ml/kg/min and gradually increased every 5-10 min by 10 ml/kg/min to reach the desired flow. Gas flow to blood flow ratio is adjusted to 0.5 : 1 & start with FiO2 of 21%  100% FiO2. Once desired flow achieved, ventilator settings are brought down to base line. SOURCE : ECMO UPTODATE 2013

46. Reasonable targets are : - an arterial oxy Hb saturation of- >90% for VA ECMO, >75% for VV ECMO - A venous oxy Hb saturation of 70-80% for VA ECMO -Adequate tissue perfusion as determined by arterial blood pressure, venous oxygen saturation and blood lactate level. SOURCE : ECMO UPTODATE 2013

47. MAINTENANCE & MONITORING : Once the initial respiratory and hemodynamic goals have been achieved, blood flow is maintained at that rate. Continuous venous oxymetry , Pressure monitoring (MAP, prepump P, pre and post oxygenator P), vital parameters (HR, RR, TEMP), Flow rates (blood flow rate at 60-150 ml/kg/min), neurological status, vascular status to be monitored. Anticoagulation is sustained during ECMO with a continuous infusion of unfractionated heparin, titrated with activated clotting time(ACT) of 180-210 sec.

48. WEANING & TRIAL OFF OF ECMO INDICATIONS : -For patients with Respiratory failure, improvements in radiographic appearance, pulmonary compliance and arterial oxyHb saturation. -With cardiac failure, enhanced aortic pulsatility correlates with improved left ventricular output. -One or more trials of taking the patient off of ECMO should be performed prior to discontinuing ECMO permanently. SOURCE : ELSO General Guidelines Version 1.3 December 2013

49. Decrease flow in steps to 1 L/min at FiO2 100% or decrease flow to 2L/min then decrease sweep gas FiO2 to maintain SaO2 >95% When SaO2 stable on these settings, - VV ECMO trials are performed by eliminating all countercurrent sweep gas through oxygenator. Blood flow remains constant, but gas transfer doesnot occur. Ventilator settings are adjusted. - VA ECMO trials need temporary clamping of both drainage and infusion lines, while allowing to circulate through a bridge between the arterial and venous limbs. - VA ECMO trials are generally shorter duration than VV ECMO trials because of higher risk of thrombus formation. SOURCE : ELSO General Guidelines Version 1.3 December 2013

50. COMPLICATIONS Bleeding Thromboembolism Cannulation related Heparin induced thrombocytopenia VV ECMO specific complications VA ECMO specific complications Neurological complications

51. BLEEDING : - Occurs in 30-40% of patients on ECMO - Due to continuous heparin infusion and platelet dysfunction. treatment : -maintaining platelet count > 1 lakh/mm3, target ACT reduces the risk of bleeding. - surgical exploration if major bleeding occurs. - if bleeding occurs, decrease heparin infusion & maintain ACT at 160 sec. - plasminogen inhibitors can be given but may increase risk of circuit thrombosis.

52. THROMBOEMBOLISM : It is more common with VA ECMO than VV ECMO as infusion is into systemic circulation. A sudden change in pressure gradient indicates thrombus formation.

53. CANNULATION RELATED : Vessel perforation with haemorrhage. Arterial dissection Bleeding Distal ischemia in VA ECMO - treatment : inserting distal perfusion cannula in femoral artery distal to ECMO cannula.

54. HEPARIN INDUCED THROMBOCYTOPENIA HIT can occur in patients receiving ECMO. When HIT is proven, heparin infusion should be replaced by non-heparin anticoagulant.

55. VV ECMO SPECIFIC COMPLICATIONS RECIRCULATION : -Here, reinfused blood is withdrawn through the drainage cannula without passing through the systemic circulation. - The degree of recirculation determines the efficiency of ECMO in providing oxygenation. I NTERVENTION : - Increasing the distance between cannulae - Use of single site double lumen cannula - Addition of another drainage cannula SOURCE : ELSO guidelines for management of recirculation May 2015

56. VA ECMO specific complications Pulmonary haemorrhage Cardiac thrombosis -retrograde blood flow in the ascending aorta in VA ECMO. -stasis of blood can occur if left ventricular output is not maintained leading to thrombosis. Coronary or cerebral hypoxia -coronary usually gets blood from native circulation (from LV) -With compromised LV & LUNGS, relatively hypoxic perfusion occurs.

57. THE HARLEQUIN SYNDROME (north south syndrome) Saturation of upper part of the body is lower than that of lower half. This is due to flow competition in the aorta – recovering heart vs ECMO pump High cardiac output from native recovering heart prevents the retrograde flow of ECMO to perfuse upper part. If pulmonary function is impaired : -”BLUE HEAD” : deoxygenated blood to upper part -”RED LEGS” : hyperoxygenated blood to lower part

58. In case of respiratory failure, flow competition in the aorta between the recovering native heart and the extracorporeal circuit can lead to a “Harlequin” or “North–South” syndrome. Christopher Lotz et al. Circulation. 2014;130:1095-1104 Copyright © American Heart Association, Inc. All rights reserved.

59. TREATMENT : -increase the ECMO flow if no cardiac stunning -higher ventilator setting or consider HFOV (High Frequency Oscillatory Ventilation) -switch to VV ECMO if persistent lung failure.

60. Chest X-ray belongs to a 19-yr-old female with ARDS on VV-ECMO. Guillermo Martinez, and Alain Vuylsteke Contin Educ Anaesth Crit Care Pain 2011;bjaceaccp.mkr056 © The Author [2011]. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: [email protected]

61. OUTCOMES OF ECMO

62. Published online : 16 September 2009

63. CESAR TRIAL Randomized control trial of adult ECMO vs Conventional Ventilatory support. Adults were randomized either to VV ECMO at Glenfield Hospital, Leicester, England (90 patients) or continuing conventional care at referral hospitals (90 patients ) i.e., conventional ventilator support. Peek  GJ, et.al. Lancet 2009;374:1351‐136

64. ECMO 57 out of 90 met primary end point. Survival rate at 6months is 63% Mortality 37% CONVENTIONAL VENTILATORY SUPPORT 41 of 87 met primary endpoint Survival rate at 6months is 47% Mortality 53% Peek GJ, et.al. Lancet 2009;374:1351‐136

65. United Kingdom H1N1 ECMO vs Conventional care 69 ECMO patients in 4 centers •Conclusion: ECMO survival 76% Conventional Care 49% Noah JAMA 2011, 366:1659

66. 68 patients with severe influenza associated ARDS were treated with ECMO. Out of 68, -influenza A - 61 (H1N1 -53) -Not subtyped -7 Survival rate : 71% (48 out of 68)

67. EXTRACORPOREAL CO2 REMOVAL (ECC02R) The process by which an extracorporeal circuit is used for the primary purpose of removing CO2 from the body, thereby providing partial respiratory support. First described in 1977 by Kolobow and Gattioni . Where as ECMO is indicated in treating refractory hypoxemia in severe cases of ARDS, ECC02R is indicated to facilitate protective ventilation in all stages of ARDS.

68. EXTRACORPOREAL CPR It is a method of cardiopulmonary resuscitation that uses ECMO as an adjunct to standard CPR. The application of ECMO allows the return of cerebral perfusion in a more suitable manner than with external compressions alone.

69. CHEER TRIAL

70. ECMO PROCEDURE

71. THANK YOU

72. SURGERY IN PULMONARY TUBERCULOSIS ON 05-02-2016 FRIDAY BY DR. SANDEEP