ECMO as a life support

By Dr.Pavan Yadav, MBBS, MD, FCCP

Title: Understanding Extracorporeal Membrane Oxygenation (ECMO)

Introduction: Extracorporeal Membrane Oxygenation (ECMO) is a life-saving technique that provides temporary support to patients with severe respiratory or cardiac failure. It is an advanced form of life support that is used in critical care settings to provide oxygenation and/or circulation support when conventional treatments are inadequate. As a healthcare professional, it's essential to have a comprehensive understanding of ECMO, its indications, contraindications, and management to provide optimal care to patients in need.

• What is ECMO?

ECMO, also known as extracorporeal life support (ECLS), is a technique that involves removing blood from the patient's body, oxygenating it, and then returning it to the body, bypassing the heart and lungs. It acts as an artificial lung and/or heart, providing oxygenation, carbon dioxide removal, and/or circulatory support, depending on the type of ECMO used. ECMO can be either veno-arterial (VA) or venovenous (VV) based on the type of cannulation and support provided.

• ECMO indications-

ECMO can be used as either a bridge to recovery or a bridge to transplantation, depending on the underlying condition and prognosis of the patient.

Bridge to Recovery: In some cases, ECMO is used as a temporary measure to support the failing heart or lungs, allowing the body time to heal and recover. This is often used in acute situations where the patient's condition is reversible, such as in cases of acute respiratory distress syndrome (ARDS) or myocarditis. ECMO provides temporary support to the heart or lungs, allowing them to rest and recover while maintaining adequate oxygenation and circulation.

During ECMO as a bridge to recovery, the healthcare team closely monitors the patient's progress, regularly reassessing the need for continued ECMO support. If the patient's condition improves, the ECMO support can be gradually weaned off, and the patient can be transitioned back to conventional medical treatments. Bridge to recovery is an ideal approach when the underlying condition causing the organ failure is reversible, and the patient is expected to regain normal organ function with time.

Bridge to Transplantation: In some cases, ECMO may be used as a bridge to transplantation, where a patient with end-stage heart or lung failure is awaiting a suitable organ for transplantation. ECMO provides temporary support to maintain the patient's vital organ functions until a suitable organ becomes available for transplantation.

Contraindications for ECMO: While ECMO is a life-saving technique, it may not be suitable for all patients. Some contraindications for ECMO include irreversible organ failure, terminal illness, untreatable malignancy, advanced age with limited life expectancy, bleeding/coagulation disorders, and irreversible neurologic injury. Additionally, ECMO may not be feasible in cases where vascular access cannot be obtained or there are significant anatomical or physiological limitations.

ECMO Management: The management of ECMO requires a highly specialized and multidisciplinary approach. Healthcare professionals involved in ECMO care should have advanced training and expertise in critical care, perfusion, and ECMO management. The following are some key considerations in ECMO management:

1. Patient Selection: Proper patient selection is critical for successful ECMO outcomes. Patients who meet the appropriate indications and do not have any contraindications should be carefully selected based on their clinical condition, comorbidities, and expected outcomes.
2. Cannulation: ECMO cannulation involves the placement of venous and/or arterial cannulas to establish extracorporeal circulation. Proper cannulation technique is crucial to prevent complications such as bleeding, infection, and limb ischemia. Monitoring of blood flow, gas exchange, and circuit pressures should be done continuously during cannulation.
3. Circuit Management: The ECMO circuit needs to be monitored and managed carefully. This includes regular assessment of circuit flows, gas exchange, circuit pressures, and anticoagulation levels. Any circuit malfunction or clotting should be addressed promptly to prevent complications.
4. Anticoagulation: Patients on ECMO require systemic anticoagulation to prevent clot formation in the circuit. Continuous monitoring of coagulation parameters, such as activated clotting time (ACT) or activated partial thromboplastin time (aPTT), is essential to maintain appropriate anticoagulation levels. However, anticoagulation management should be carefully balanced to prevent bleeding complications.
5. Ventilator Management: Patients on ECMO may still require mechanical ventilation to support their respiratory function.

• The weaning process

It is a critical step in the management of patients who have received ECMO support. ECMO weaning involves gradually reducing the level of support provided by the ECMO machine until the patient's heart and/or lungs are able to function independently again. The weaning process requires careful monitoring and assessment by a multidisciplinary healthcare team, and it should be tailored to the individual patient's condition and response to treatment.

Here are some key aspects of the ECMO weaning process:

Assessment of Patient Readiness: Before initiating the weaning process, the healthcare team must assess whether the patient is physiologically stable and ready for ECMO weaning. This includes evaluating the patient's vital signs, laboratory results, and overall clinical condition. The patient should have stable heart and lung function, adequate oxygenation and ventilation, and no significant organ dysfunction.

Gradual Reduction of ECMO Support: The weaning process typically involves gradually reducing the level of support provided by the ECMO machine. This can be done by reducing the flow rates or changing the ECMO circuit configuration to decrease the amount of support provided to the heart and/or lungs. The reduction in ECMO support is usually done in small increments over time, while closely monitoring the patient's response and adjusting accordingly.

Assessment of Organ Function: Throughout the weaning process, the healthcare team closely monitors the patient's heart and lung function. This includes regular assessments of cardiac output, pulmonary function, and gas exchange. If the patient's organ function remains stable during the weaning process, it may be an indication that they are ready to be weaned off ECMO.

Gradual Decannulation: Decannulation refers to the removal of the cannulas, which are the tubes that connect the patient's blood vessels to the ECMO circuit. Decannulation is typically done gradually, with one cannula removed at a time, while carefully monitoring the patient's hemodynamic stability. The decannulation process requires expertise and coordination among the healthcare team to prevent complications and ensure patient safety.

Continued Monitoring: Even after the patient has been weaned off ECMO and the cannulas have been removed, close monitoring continues to assess the patient's cardiac and pulmonary function. This includes monitoring vital signs, oxygenation, ventilation, and organ function. If the patient remains stable and maintains adequate organ function after decannulation, they may be considered successfully weaned from ECMO.

Rehabilitation and Follow-up: Once the patient has been successfully weaned from ECMO, rehabilitation and follow-up care are crucial for their recovery. This may include physical and respiratory therapy to restore strength and function, as well as ongoing monitoring of cardiac and pulmonary function. Regular follow-up appointments with the healthcare team are important to monitor the patient's progress and address any ongoing needs.

• Complications

They can arise during the use of ECMO, a complex and invasive therapy. Here are some potential complications that healthcare professionals should be aware of:

1. Bleeding and Hemorrhage: Due to the use of anticoagulants during ECMO to prevent clotting in the extracorporeal circuit, bleeding, and hemorrhage can occur. This can range from minor bleeding at cannula insertion sites to more serious bleeding into vital organs, such as the brain or gastrointestinal tract. Close monitoring of coagulation parameters and careful management of anticoagulation is important to minimize the risk of bleeding complications.
2. Infection: Infections can occur in patients receiving ECMO, as the extracorporeal circuit provides a potential route for bacteria or other pathogens to enter the bloodstream. Infections can range from local infections at the cannula insertion sites to bloodstream infections, which can be severe and life-threatening. Strict adherence to infection prevention protocols, including aseptic technique during ECMO cannulation and regular monitoring for signs of infection, is essential.
3. Organ Dysfunction: ECMO can place stress on the heart, lungs, and other organs, which may result in organ dysfunction. Cardiac arrhythmias, acute kidney injury, liver dysfunction, and lung injury are potential complications associated with ECMO. Close monitoring of organ function and prompt intervention if organ dysfunction is detected is important to prevent further complications and optimize patient outcomes.
4. Neurological Complications: ECMO can be associated with neurological complications, ranging from minor issues such as transient confusion or agitation to more severe complications such as stroke or brain injury. Monitoring of neurological status, including frequent neurologic assessments, is important to promptly identify any neurological changes and initiate appropriate interventions.
5. Cannula-Related Complications: Complications related to the placement and maintenance of the cannulas used in ECMO can also occur. These can include issues such as cannula malposition, dislodgement, kinking, or mechanical damage to blood vessels. Careful insertion and management of cannulas, along with regular monitoring for any cannula-related issues, are important to prevent complications and ensure proper ECMO function.
6. Hemolysis: The mechanical stress of blood passing through the ECMO circuit can cause hemolysis, which is the destruction of red blood cells. Hemolysis can lead to anemia, jaundice, and other complications. Monitoring for signs of hemolysis, such as changes in hemoglobin levels or increased bilirubin levels, and adjusting ECMO settings as needed can help prevent hemolysis-related complications.
7. Psychosocial Complications: Patients and their families may experience significant emotional and psychological stress during ECMO support, including anxiety, depression, and post-traumatic stress disorder (PTSD). Providing appropriate psychological support and counseling to patients and their families is crucial to address these psychosocial complications and promoting overall well-being.

• Conclusion -

ECMO is a valuable tool in critical care management, providing temporary support to patients with severe heart or lung failure. It can be used as a bridge to recovery in cases where the patient's condition is expected to improve with time, allowing the heart or lungs to recover normal function. It can also be used as a bridge to transplantation in cases where the patient is awaiting a suitable organ for transplantation. As a healthcare professional, understanding the different applications of ECMO as a bridge to recovery or a bridge to transplantation is crucial in providing optimal care to critically ill patients. Careful patient selection, regular monitoring, and multidisciplinary management are essential components of ECMO care in both scenarios.