Extracorporeal membrane oxygenation (ECMO) or extracorporeal life support (ECLS) is a technique of providing both cardiac and respiratory support to patients whose heart and lungs are unable to provide an adequate amount of gas exchange to sustain life. This intervention has mostly been used on pediatric patients, but it is seeing more use in adult patients with cardiac and respiratory failure. ECMO works to remove the carbon dioxide from the blood and oxygenate it. Generally it is only used in the later treatment of a person with heart or lung failure as it is solely a life-sustaining intervention.
Two modes are available: veno-arterial and veno-venous.
In veno-arterial ECMO – a venous cannula is usually placed in the right common femoral vein for extraction and an arterial cannula is usually placed into the right femoral artery for infusion. Central VA ECMO may be used if cardiopulmonary bypass has already been established (with cannulae in the right atrium and ascending aorta)
In veno-venous ECMO cannulae are usually placed in the right common femoral vein for drainage and right internal jugular vein for infusion. Alternatively, a dual lumen catheter is inserted into the right internal jugular vein, draining blood from the superior and inferior vena cavae and returning it to the right atrium. This is used in respiratory failure.
With acute respiratory failure use of ECMO has been shown to improve survival rates. Survival rates from 50—70 percent have been reported in observational and uncontrolled clinical trials. The survival rates reported are better than historical survival rates.
Guidelines that describe the indications and practice of ECMO are published by the Extracorporeal Life Support Organization (ELSO). Criteria for the initiation of ECMO include acute severe cardiac or pulmonary failure that is potentially reversible and unresponsive to conventional management.
Examples of clinical situations that may prompt the initiation of ECMO include the following:
• Hypoxemic respiratory failure with a ratio of arterial oxygen tension to fraction of inspired oxygen (PaO2/FiO2) of <100 mmHg despite optimization of the ventilator settings, including the Fraction of Inspired Oxygen (FiO2), positive end-expiratory pressure (PEEP), and inspiratory to expiratory (I:E) ratio.
• Hypercapnic respiratory failure with an arterial pH <7.20.
• Refractory cardiogenic shock.
• Cardiac arrest.
• Failure to wean from cardiopulmonary bypass after cardiac surgery.
• As a bridge to either cardiac transplantation or placement of a ventricular assist device.
I hope you enjoyed the challenege of this unusual sighting which may not be seen except in advanced care centers.
Special thanks to Dr. Elie Chammas who was the only person willing to venture and suggest an explanation....