Extracorporeal membrane oxygenation (ECMO) is lifesaving support
Extracorporeal membrane oxygenation (ECMO) is lifesaving support; patients may be already intubated prior to ECMO. In some life-threatening situations, ventilator support is not sufficient to keep up blood oxygen levels. This is where ECMO can play a role. ECMO is not a definitive treatment, but it can provide time for the heart and lungs to recuperate. It is only used when the patient’s condition can improve with rest.
- Patients who are on ECMO are already connected to a ventilator (breathing machine) through a tube (endotracheal or ET tube) that is placed in the mouth or nose and down into the windpipe. They are thus intubated.
- It is an advanced type of mechanical life support that removes blood from the body, oxygenates and removes carbon dioxide from that blood, and then returns the blood to the body, allowing the patient’s damaged lungs/heart time to recover. There are two types of ECMO:
- Veno-arterial (VA) ECMO: Blood drains from a vein and returns through an artery. It can support heart and lung function.
- Veno-venous (VV) ECMO: Blood drains from and returns to a vein. This type is used primarily to rest the lungs.
- The doctor will give the patient medication to prevent pain before and during the procedure. The doctor gives them medicine to keep them calm while ECMO is in use. If necessary, the doctor may also give extra medicine to relax them.
- The doctor may place cannula or tubes into large vessels in the patient’s neck. These tubes are connected to the ECMO circuit.
- The patient’s blood slowly drains into the circuit and is circulated through an artificial lung, where oxygen and carbon dioxide are exchanged. The blood circulates through a warmer before returning to the patient.
- Once ECMO flow is established, the doctor may turn down the ventilator settings to allow the lungs to rest.
- As soon as the correct ECMO flow is reached, the doctor may adjust the ventilator to let the lungs rest. The ventilator settings may remain low until the patient is ready to come off ECMO. The healing process for the lungs may take several days or weeks.
- As the patient improves, the doctor may decrease the ECMO flow to allow the heart and/or lungs to work better.
- As the patient improves, the doctor may adjust the ECMO oxygenator by decreasing the amount of gas delivered across the membrane to allow the lungs to do more of the work. The length of time on ECMO varies for each patient.
- While the patient is on ECMO, the doctor may continuously monitor them. They will still be very sick and require intensive care. The doctor or the technician will do the lab work and take X-rays of the patient’s lungs daily to determine the improvement and progress.
- The doctor then gives heparin, a drug that prevents blood clotting, to the patient on ECMO. The amount of heparin varies with each patient and is closely monitored. Frequent adjustments are made in the amount needed.
- The doctor performs an ultrasound of the patient’s head to check for abnormal bleeding. They may also perform ultrasounds, if necessary, of the kidneys and heart.
- Transfusions are needed to keep the patient’s blood count at a normal level. The doctor regularly gives platelets, a blood product that helps with clotting, to all patients on ECMO.
- The doctor can give all medications and draw the laboratory work without sticking the patient. There are several connections on the ECMO circuit where medications are given and blood drawn.
- The doctor may or may not decrease medications to help the heart function. The doctor will change medications for each patient based on individual needs.
When is extracorporeal membrane oxygenation necessary?
Extracorporeal membrane oxygenation (ECMO) is necessary when a patient has severe lung or heart problems, and the standard forms of treatment are not effective. If a patient shows no improvement, ECMO may have to be stopped. Some of the illnesses and situations for which ECMO is used include:
- Postoperative cardiac surgery
- Pneumonia (due to infection)
Babies who need ECMO may have one of the following conditions:
- Congenital diaphragmatic hernia (CDH)
- Meconium aspiration syndrome (MAS)
- Pulmonary hypertension (PPHN/PAH)
- Inborn errors of metabolism
In about 20% of cases, babies and patient’s do not improve even with the use of ECMO. Sometimes, a complex problem is not diagnosed until after ECMO has begun. For most of those who are on ECMO, it is a last-ditch effort.
- The blood thinners used during ECMO can lead to bleeding that is hard to control.
- It is particularly dangerous if there is bleeding in the heart, brain, or intestines, and surgery is sometimes required to contain the bleeding.
- Infections are always a concern when external tubes are placed in the body; with ECMO, infections can penetrate vital organs and cause serious issues.
- Strokes can also occur if the brain blood supply is compromised or clots are formed in the tubes. Similarly, kidney damage can occur if sufficient blood doesn’t reach the organ.
- ECMO is one of the costliest and most resource-intensive treatments in health care, and some patients may need to be on it for weeks. Given the already strained health infrastructure and poor prognosis of patients, some tough decisions may need to be taken about whether ECMO can be deployed widely at all.