ECMO is used when a patient in respiratory or cardiac failure does not respond to conventional therapies.
Common conditions that may require ECMO are:
- Meconium Aspiration Syndrome
- Congenital Diaphragmatic Hernia
- Severe and/or Persistent Pulmonary Hypertension
- Certain Congenital Heart Defects
- Failure to Wean from Cardio-Pulmonary Bypass
- Any Form of Respiratory Failure
- Severe Sepsis
Types of ECMO
There are generally two types of ECMO:
Veno-Venous (VV) – This method of ECMO support is used primarily to support respiratory failure that lacks a cardiac failure component. The most common vessels cannulated are the internal jugular and/or the femoral vein.
Veno-Arterial (VA) – This method is used to support the respiratory and cardiovascular systems in the event of complete failure. The most common vessels cannulated can include the carotid artery, aortic arch, or femoral artery along with the internal jugular, right atrium, or femoral vein.
What it is ECMO?
ECMO (Extracorporeal Membrane Oxygenation) aka ECLS (Extracorporeal Life Support) utilizes equipment similar to that used in cardio-pulmonary bypass during heart surgery. We are able to perform this therapy in the Neonatal and Pediatric Intensive Care Units at RMHC at P/SL.
How ECMO Works
The blood is removed from the patient by a combination of gravitational pull and negative pressures created by the roller head. The machine is servo-regulated by various pressure monitors and a flexible PVC bladder that reduce the pressure fluctuations to the patient.
After the blood is displaced by the roller head, it is shunted through a hemofilter that can remove excess fluid and toxins, if necessary. It then enters the membrane oxygenator to provide gas exchange. This allows mechanical ventilation settings to be reduced, limiting barotrauma and allowing time for healing.
The goal is to maintain a level of inflation that will prohibit atelectasis, but limits over distention that is common in patients in respiratory failure that require elevated settings to achieve gas exchange.
If providing cardiac support, it is not uncommon for inotropic support to be significantly reduced or discontinued, which can significantly limit side effects common to those medications.
For blood to be removed from the body into a PVC circuit, there has to be a degree of anticoagulation. This is achieved by a continuous infusion of Heparin and frequent monitoring of clotting times.
ECMO Patient Selection
Due to the severe nature of ECMO support, there is a standard of selection criteria to ensure that patients who are unlikely to have long-term benefits are not subjected to unnecessary therapy.
A risk to benefit analysis of each case is important and early consultation with ECMO physicians at RMHC is important as soon as it is recognized that a patient is not responding to conventional therapy.
ECMO Patient Selection Criteria
The standard criteria for patient selection has been established by ELSO (Extracorporeal Life Support Organization) after years of statistical evaluation of patients who have had ECMO support.
- Gestational age greater than or equal to 34 weeks
- Birth weight greater than or equal to 2,000 grams
- Lack of coagulopathy or bleeding issues
- No major intracranial hemorrhage (Grade I and II bleeds are considered on a case-by-case basis)
- Ventilation less than 14 days with reversible lung disease
- No lethal congenital anomalies
- No uncorrectable cardiac lesions
- No evidence of irreversible brain damage (patients with conditions such as Trisomy-21 are determined on a case-by-case basis with consideration of prior and potential continued quality of life)
Muers, K.V., et al; ECMO – Extracorporeal Cardiopulmonary Support in Critical Care 3rd ed; 2005.
How Long does ECMO Last?
Cardiac (heart) conditions are frequently off of ECMO support in three to five days. However, patients with certain conditions such as severe pneumonias or pulmonary hypertension can be on for weeks. There is not a defined stop time, but is determined by either recovery or failure to see any improvement over a period of time.
Risks and Benefits of ECMO
If ECMO support is recommended for your child, please discuss the risks and benefits with your child’s doctor.