608770180-ECHMO.pptx detailed explanation

Extra corporial membrane oxygenation

1. ECMO By, ANUPAMA.VARGHESE Ist YEAR MSC NURSING BBCON

2. 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.

3. DEFINITION ECMO is temporary support of heart and lung function by partial cardiopulmonary bypass (up to 75% of cardiac output). It is used for patients who have reversible cardiopulmonary failure from pulmonary, cardiac or other disease.

4. PHYSIOLOGY Blood is drained from the patient to an external pump which pushes the blood through a membrane gas exchanger (for oxygenation and CO2 removal) and warmer and returns the blood to the patient’s circulation. The method requires heparin anticoagulation of the patient, that is managed by frequent measurements of activated clotting time (ACT). Various devices monitor pressures, flow, and temperature of the ECMO blood and gas circuits, as well as physiological variables in the patient.

5. ECMO PRINCIPLE • Desaturated blood is drained via a venous cannula • CO2 is removed, O2 added through an “extracorporeal” device • The blood is then returned to systemic circulation via another vein (VV ECMO) or artery (VA ECMO).

6. ECMO PRINCIPLE • Desaturated blood is drained via a venous cannula • CO2 is removed, O2 added through an “extracorporeal” device • The blood is then returned to systemic circulation via another vein (VV ECMO) or artery (VA ECMO).

7. PRE-ECMO ASSESSMENT chest x-ray and arterial pH and blood gas measurements Physical examination with careful neurological examination PT, PTT, fibrinogen, CBC with platelets, electrolytes, Ca, BUN, Creatinine Cranial ultrasound Echocardiogram

8. 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.

9. ECMO CIRCUIT & COMPONENTS The basic components of ECMO circuit includes: • a blood pump • membrane oxygenator & heat exchanger • controller • cannulas • tubing's

10. PUMPS They are basically of 3 types: • Roller pump • Impellar pump •centrifugal pump

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

12. 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

13. GAS EXCHANGE : CO2 exchange depends on : Difference in CO2 conc. between blood and gas • Size of membrane • Fresh gas flow • Blood pathway thickness • Blood flow rate

14. HEAT EXCHANGER : • In adults, it is usually built within the oxygenator. • In pediatric cases, it is connected separately after the oxygenator in the circuit. • It is used for temperature regulation of the extracorporeal blood. • Controller panel for pressure monitoring and blood gas monitoring

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

16. 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

17. Different CONFIGURATIONS in ECMO 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

18. 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]

19. 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.

20. INDICATIONS OF ECMO Acute severe cardiac failure or respiratory failure with high mortality risk and reversible and non-responsive to optimal conventional therapy. In hypoxic resp failure due to any cause CO2 retention on Mechanical Ventilation Need for intubation in a patient on lung transplant list Immediate cardiac or respiratory collapse (Pulmonary Embolism, blocked airway) unresponsive to optimal care

21. Reversible Respiratory Failure : • ARDS • Severe Pneumonias • Severe Acute Asthma • Chemical and Inhalation hypersensitivity Pneumonitis • Near Drowning • Post traumatic Lung Contusion • Autoimmune lung disease

22. Irreversible or Chronic Respiratory Failure : It is indicated as a bridge, only when a patient is for lung assist device. Eg : patient is waiting for lung transplant.

23. CONTRAINDICATIONS • No absolute contraindications to ECLS in respiratory failure. Relative contraindications due to poor outcome are : Mechanical Ventilation at high settings ( FiO2 >90%) for 7 days or more. Major pharmacological immunosuppression (absolute neutrophil count < 400/mm3) CNS hemorrhage 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

24. ECMO MECHANISM It includes : INITIATION MAINTENANCE DISCONTINUATION

25. 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 • Once desired flow achieved, ventilator settings are brought down to base line.

26. MAINTENANCE & MONITORING: • Once the initial respiratory and hemodynamic goals have been achieved, blood flow is maintained at that rate. • Continuous venous oximetry, Pressure monitoring (MAP, pre-pump 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.

27. WEANING & TRIAL OFF OF ECMO INDICATIONS : For patients with Respiratory failure With cardiac failure. One or more trials of taking the patient off of ECMO should be performed prior to discontinuing ECMO permanently

28. COMPLICATIONS • Bleeding: Occurs in 30-40% of patients on ECMO - Due to continuous heparin infusion and platelet dysfunction. • 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 • Cannulation related: Vessel perforation with haemorrhage , Arterial dissection , Bleeding .

29. VA ECMO specific complications • 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. Heparin induced thrombocytopenia

30. 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” : hyper oxygenated blood to lower part.

31. NURSING MANAGEMENT

32. Nursing implications for cannula site management Skin integrity implications in ECMO patients Early mobility in ECMO Nursing implications for detection and prevention of systemic complications related to ECMO Nursing implications in ethics and ECMO withdrawal.

33. Nursing implications for cannula site management Nursing care should include monitoring of the ECMO circuit as nurses and associated staff, such as respiratory therapists and perfusionists, are at the bedside with the patient continually. assessment for erythema, purulence, adequacy of securement, and dressing integrity. It is significantly important to monitor for fixation of the ECMO cannulae . Initial placement of ECMO cannulae is usually confirmed by echocardiography and the position reaffirmed by radiographs

34. Disruption of innate circulatory flow secondary to ECMO can result in limb ischemia. Thus, it is important to monitor limbs, especially those distal from cannulation sites. site assessment, as well as assessment of the abdomen, flanks, and inguinal areas for ecchymosis, hypotension, and acutely worsening anemia, is necessary

35. Skin integrity implications in ECMO patients Patients need to be turned and repositioned every 2 h as tolerated. Turns should be scheduled and require a multidisciplinary team to ensure patient safety. Silicone gel adhesive dressings should be utilized when possible and can be applied on the sacrum, elbows, and heels.

36. Early mobility in ECMO Early physical rehabilitation and mobility implemented in patients receiving ECMO support have been shown to significantly improve patient outcomes

37. Nursing implications for detection and prevention of systemic complications related to ECMO Renal and other intraabdominal complications: The bedside RN can assist in early identification of AKI by monitoring urine output; measuring strict fluid intake and output; assessing serial serum chemistry values, particularly serum creatinine and trends of electrolyte dyscrasias; and identifying physical exam findings consistent with fluid overload.

38. Hematological complications With the significant risk for bleeding and the subsequent need for anticoagulation, nursing can expect regular and repeated blood draws, transfusions, and anticoagulant titration to be a part of their daily practice in the care of the ECMO patient.

39. Nursing implications in ethics and ECMO withdrawal Communication is the key in healthcare. An integral part of communication is developing and maintaining a team not isolated to healthcare workers but also including the patient and family. Early involvement of the palliative care team and social work is crucial to providing consistent support to the patient and family. Interdisciplinary daily rounds including the bedside nurse, family members, palliative care team, and social work are integral to find commonalities for all regarding goals of care.