What is ECMO?
ECMO is a procedure in which the blood is pumped out of the body to a heart-lung machine. The process involves removing carbon dioxide and sending back oxygen-rich blood to the body. The blood that flows from the right side of the heart to the membrane oxygenator is also rewarmed before sending it back to the body.
What is the purpose of ECMO?
When the heart and lung are being healed and cured, they need rest. It’s in this scenario ECMO is used.
When is ECMO used?
There are various conditions of the heart and lungs that warrant the use of ECMO. In addition to these, ECMO is also used for people who have opted for or recovering from a heart transplant. When other life supporting measures don’t work, doctors use ECMO.
ECMO is used in Covid-19 treatment as well as in cases of acute respiratory distress syndrome. Let’s take a look at some of the most common heart conditions for which ECMO is used.
- Acute myocardial infarction, commonly known as heart attack
- Decompensated cardiomyopathy i.e. heart muscle disease
- Myocarditis or inflammation of the heart muscle
- Sepsis – a life-threatening conditions caused by the body’s response to infections
- Severe hypothermia, a condition characterised by extremely low body temperature
- Post-transplant complications
- Cardiogenic shock, as a result of the heart not pumping enough blood
Lung conditions for which ECMO is preferred are as follows:
- Acute respiratory distress syndrome (ARDS)
- Blockage in a pulmonary artery in the lungs, also known as pulmonary embolism
- Defect in the diaphragm which causes congenital diaphragmatic hernia
- Meconium aspiration – a rare occurrence in which the foetus inhales waste products in the womb
- Complicated cases of common flu
- Hantavirus pulmonary syndrome
- Pulmonary hypertension
- Respiratory failure
The risk factors
With advancements in technology and subsequent improvements in the device as well as years of experience of the healthcare professional, risk factors associated with ECMO are on a decrease these days. Nevertheless, the risk factors are not ruled out completely. Let’s take a look at some of the risk factors.
- Blood clot
- Blood clotting disorder
- Loss of blood in hands, feet or legs
- Stroke – the brain gets damaged either due to loss of blood or when a blood vessel bursts
ECMO – the procedure
ECMO is an invasive procedure. The doctor will insert a thin flexible tube known as a cannula into a vein. The purpose of this cannula is to draw out blood and hence, it’s called the drainage cannula. A secondary cannula will also be inserted to send back blood to the body which is warmed and oxygenated.
ECMO is suggested for patients who have undergone surgery or who have severe complications with regard to their heart/lungs health.
ECMO is found to be very effective in newborns. In fact, newborns are the principal age group for which ECMO therapy is much superior to conventional therapy. Some of the neonatal conditions that require ECMO are primary pulmonary hypertension (PPHN), including idiopathic PPHN, meconium aspiration syndrome, respiratory distress syndrome and asphyxia and congenital diaphragmatic hernia (CDH).
As a procedure, ECMO has evolved tremendously over the years. Improved understanding of the benefits of ECMO has resulted in its widespread use as a rescue therapy. ECMO has saved an innumerable number of patients with ARDS and refractory hypoxemia associated with H1N1/2009 infection (‘swine flu’).
Dr. Prakash V S | Professor, HOD- Department of Cardiology & Consultant – Cardiology – Adult, Electrophysiology | M S Ramaiah Narayana Heart Centre, M S Ramaiah Nagar, Bangalore