ECMO stands for Extracorporeal Membrane Oxygenation, a form of mechanical life support that provides full respiratory bypass in patients with severe respiratory failure as a bridge to recovery or lung transplantation. ECMO pumps blood from the patient’s body to an artificial lung that adds oxygen to it and removes carbon dioxide, thus replacing the function of the person’s own lungs. The ECMO machine then sends the blood back to the patient via a pump with the same force as the heart, replacing its function.
ECMO can be a lifesaver therapy and a last hope to individuals battling conditions such as severe pneumonia, acute respiratory distress syndrome (ARDS), and cardiac failure. ECMO gained prominence during the swine flu endemic and emerged as a crucial treatment during the Covid pandemic, acting as a lifeline for patients and facilitating lung transplants when necessary.
When is ECMO Used and Who Can Benefit from It?
ECMO is used when conventional treatments, such as mechanical ventilation and medications, fail to improve the patient’s condition and the risk of death is high. ECMO can provide temporary support for the lungs and/or the heart, allowing them to rest and heal while the underlying cause of the failure is treated. ECMO can also be used as a bridge to lung transplantation, providing oxygenation and stability for the patient until a suitable donor organ is available.
ECMO can benefit patients with potentially reversible causes of respiratory failure, such as ARDS, severe pneumonia, pulmonary embolism, trauma, aspiration, or inhalation injury. ECMO can also benefit patients with cardiogenic shock or cardiac arrest who do not respond to other forms of resuscitation. However, ECMO is not suitable for everyone and has strict criteria for patient selection. Factors such as age, comorbidities, duration of illness, and prognosis are considered before initiating ECMO.
What are the Risks and Complications of ECMO?
ECMO is a complex and invasive procedure that carries significant risks and complications. Some of the common complications include bleeding, infection, thrombosis, hemolysis, and neurological injury. Bleeding can occur at the site of cannulation, where the tubes are inserted into the blood vessels, or in other organs such as the brain, lungs, or gastrointestinal tract. Infection can occur due to the presence of foreign material in the bloodstream or the exposure of the patient to the external environment. Thrombosis, or blood clotting, can occur in the ECMO circuit or in the patient’s own vessels, leading to obstruction or embolism. Hemolysis, or the breakdown of red blood cells, can occur due to the mechanical stress of the ECMO pump or the oxygenator, resulting in anemia and kidney injury. Neurological injury can occur due to bleeding, embolism, or hypoxia in the brain, causing stroke, seizures, or brain death.
ECMO also has potential adverse effects on the patient’s own organs, such as the lungs, the heart, the kidneys, and the liver. ECMO can cause lung injury due to the high pressure and flow of blood in the pulmonary circulation, or due to the loss of normal lung function and ventilation. ECMO can also cause cardiac dysfunction due to the alteration of preload, afterload, and contractility of the heart, or due to the development of arrhythmias or cardiac tamponade. ECMO can also impair kidney and liver function due to the reduced blood flow to these organs, or due to the accumulation of toxins and metabolic waste products in the blood.
How is ECMO Managed and Monitored?
ECMO requires a multidisciplinary team of trained and experienced professionals, including intensivists, surgeons, perfusionists, nurses, respiratory therapists, and physiotherapists. ECMO management and monitoring involves adjusting the settings of the ECMO machine, such as the blood flow, the oxygen concentration, and the anticoagulation level, according to the patient’s condition and needs. ECMO management also involves providing supportive care to the patient, such as sedation, analgesia, nutrition, fluid balance, infection control, and wound care. ECMO monitoring involves measuring the patient’s vital signs, blood gases, hemoglobin, electrolytes, coagulation, and organ function, as well as performing regular imaging and laboratory tests.
ECMO management and monitoring also involves assessing the patient’s readiness for weaning and decannulation, or the removal of the ECMO tubes. Weaning is the gradual reduction of the ECMO support and the increase of the patient’s own lung and/or heart function. Weaning criteria include the improvement of the underlying cause of the failure, the resolution of the inflammation and edema, the restoration of the gas exchange and hemodynamics, and the absence of major complications. Decannulation is the surgical removal of the ECMO tubes from the blood vessels, which requires careful hemostasis and wound closure. Decannulation can be performed at the bedside or in the operating room, depending on the patient’s stability and the type of cannulation.