Extracorporeal membrane oxygenation (ECMO) support is now being used in several hospitals to help severe COVID patients, who have acute pneumonia or lung damage, and in cases where ventilators are failing to maintain blood oxygen levels. The support technology, which was traditionally used by cardiologists in cases of post-cardiopulmonary bypass or as a last stage support mechanism for those on the path of heart and/or lung failure, is now giving a new lease of life to many COVID patients.
What is ECMO?
Dr Suresh Rao, Co-Director of Heart and Lung Transplant at MGM Chennai, told News18.com that ECMO support is basically an artificial lung outside the patient’s body. It is not a treatment for the lungs, but only a support system/technology to do the function of the lungs so that the damaged lung(s) can rest and heal. Therefore, it is often referred to as ‘the bridge to recovery.’
“In COVID, the main affected organs are lungs, and the function of the lungs is to remove carbon dioxide and incorporate oxygen. The oxygenated blood is then carried to all other organs. Therefore, when the lung is failing, there is no oxygen support to all the organs and the carbon dioxide piles up inside the body. In such situations, we use Extracorporeal membrane oxygenation (ECMO) support," said Rao.
“Usually, when the lungs are failing, the saturation level of oxygen in the blood will fall. Under such circumstances, we first administer oxygen by mask. However, if we observe that after giving oxygen by mask, the saturation is still low, then we give high flow nasal oxygen. If, after high flow nasal oxygen too, the oxygen saturation doesn’t increase or stabilise, we put the patient on a non-invasive ventilator (NIV) like the BiPAP machine. If that fails too, we put them on invasive ventilators by connecting an oxygen pipe to the patient’s trachea. If after all this, the saturation is very low, and the patient’s condition is constantly deteriorating, and if we do not do anything, we might lose the patients, it is then that we put them on ECMO support," he added.
How Does ECMO Help Severe COVID-19 Patients?
Dr Subhash Chandra, Chairman, Cardiology BLK-Max Super Speciality Hospital, told News18.com, “In COVID cases, where a part of the lung(s) is damaged due to COVID induced Acute respiratory distress syndrome (ARDS), cytokine storm, and/or hypercoagulability, one has to give rest to such lungs, till the time it heals considerably (with medication and rest) to do its own function without any external support. Until that happens, we transfer the function of the lungs to the ECMO machine, which oxygenates the blood from the patient’s body as lungs do, and then sends it back to other organs. Therefore, ECMO is a kind of auxiliary lung or a lung outside your body," he explained.
“Apart from lungs, some COVID patients also have a circulatory failure, which means that their lungs are already in bad shape, and their arterial blood pressure is not supporting their body either. In such cases, the patients require a VA ECMO (Venoarterial Extracorporeal Membrane Oxygenation) instead of VV (venovenous) ECMO support. VA-ECMO support not only helps the lungs but also the circulation of the patients. So, when a patient is in shock, along with respiratory distress, he will be given a VA ECMO. And if a patient has only lung damage, with maintained blood pressure, he will be given VV ECMO," Dr Chandra pointed out.
What are the side effects of ECMO, And Is It Affordable?
The adverse effect of putting a patient on ECMO would be that there are chances of exaggerating coagulation, so the patient will have to be given many blood thinners. “During COVID, especially in severe cases, the immunity of patients is already low, so they are prone to various secondary infections. Therefore, if someone is put on ECMO support, he/she would need constant monitoring." Said Dr Chandra.
“The ECMO treatment is a dedicated program that runs in speciality hospitals and some big hospitals. In bigger government-run hospitals, ECMO treatments are also available. The initial cost of availing this technology is about four lakhs, and the per-day cost of keeping this support is about fifty thousand." He added.
“The longer the patient is on ECMO, the more chances there are of complications to arise. An ELSO registry also shows that the overall performance of ECMO in severe covid patients is not too good, “said the doctor.
What Happens If ECMO Fails?
If the lung(s) of the patient fails to heal in the long run, then the patient is generally recommended to go for a lung transplant. Off late, lung transplants are happening in India, especially in Southern states. However, it is logistically an expensive and challenging process, and it is not easy to get lungs as well.