Extracorporeal Membrane Oxygenation, known as ECMO, is a life support system that aids individuals experiencing severe heart or lung failure. This medical technology functions by circulating a patient’s blood outside their body, removing carbon dioxide and adding oxygen, performing the work of the lungs and sometimes the heart. ECMO provides temporary support, allowing the patient’s organs to rest and recover from illness or injury.
What Determines ECMO Duration
The duration a patient remains on an ECMO machine varies considerably, with no fixed maximum limit. Several factors influence the length of ECMO treatment, including the underlying medical condition, patient response, organ recovery rate, and complications. While some patients may require ECMO for only a few hours, others might need it for weeks or even months.
For patients with acute respiratory distress syndrome (ARDS), venovenous (VV) ECMO support typically ranges from 7 to 10 days, though some cases extend over 50 days. For severe cardiac failure, venoarterial (VA) ECMO is often used, and average support is typically 5 to 10 days, with some patients requiring several weeks. One study indicated an average ECMO support duration of about 2.14 days, showing many instances are short-term, though a small percentage require longer support.
Improvements in organ function, such as lung recovery and improved gas exchange, are continuously monitored. Complications like bleeding or infection can prolong support or lead to a decision to transition off ECMO.
Care and Monitoring on ECMO
Patients receiving ECMO support require continuous medical care. Anticoagulation is essential to prevent blood clots in the ECMO circuit and patient’s body. Unfractionated heparin is commonly used, with dosages adjusted based on frequent monitoring to balance clotting risk against bleeding. Avoiding excessive bleeding is a common complication.
Fluid management is important for adequate blood flow through the ECMO circuit and patient stability. Patients are monitored for fluid overload, which can worsen outcomes. While fluid administration is sometimes necessary, clinicians strive for a balanced approach to prevent complications.
Preventing infections is a concern due to the invasive nature of ECMO and weakened immune systems. Strict aseptic techniques and comprehensive infection prevention strategies, including cannula site care, minimize risks. Despite these efforts, infections like ventilator-associated pneumonia and bloodstream infections remain a challenge.
Nutritional support is important for ECMO patients, who are often hypermetabolic and at risk of malnutrition. Early enteral nutrition is preferred to support gut health and provide calories and protein. If not tolerated, parenteral nutrition meets metabolic demands.
Transitioning Off ECMO and Recovery
Transitioning a patient off ECMO, known as weaning, begins when their heart and lungs show signs of recovery and can resume their functions. This involves slowly reducing ECMO support while observing the patient’s physiological responses.
For patients on VV ECMO, gas flow to the oxygenator is decreased, allowing the lungs to take over gas exchange. In VA ECMO, blood flow is reduced, assessing the heart’s ability to pump blood on its own.
During weaning trials, the medical team monitors parameters like oxygen levels, breathing patterns, heart function, and blood pressure to ensure stability. If the patient struggles, ECMO support can be increased again.
Once the patient is stable with minimal or no ECMO support, the cannulas are removed. This decannulation procedure is often performed at the bedside or in an operating theater.
Recovery after ECMO is a demanding and prolonged journey, often involving additional time in intensive care and a move to a general ward. Rehabilitation, including physical and occupational therapy, helps patients regain strength, mobility, and independence. Many patients experience lingering symptoms like weakness, anxiety, sleep disturbances, and cognitive changes, which can persist for months. While initial survival rates have improved, long-term outcomes and quality of life vary, underscoring the importance of ongoing follow-up and support for survivors.