ECMO In intensive care medicine, extracorporeal membrane oxygenation (ECMO) is a technique of providing both cardiac and respiratory support oxygen to patients whose heart and lungs are so severely diseased that they can no longer serve their function.

An ECMO machine is similar to a heart-lung machine. To initiate ECMO, cannulae are placed in large blood vessels to provide access to the patient's blood. Anticoagulant drugs (usually heparin) are given to prevent blood clotting. The ECMO machine continuously pumps blood from the patient through a "membrane oxygenator" that imitates the gas exchange process of the lungs, i.e. it removes carbon dioxide and adds oxygen. Oxygenated blood is then returned to the patient.

There are two forms of ECMO Veno Arterial (VA) which provides both cardiac and respiratory support and Veno Venous (VV) which provides only respiratory support

VV ECMO can provide sufficient oxygenation for several weeks, allowing diseased lungs to heal while the potential additional injury of aggressive mechanical ventilation is avoided. It may therefore be life-saving for some patients. However, due to the high technical demands, cost, and risk of complications (such as bleeding under anticoagulant medication), ECMO is usually only considered as a last resort therapy.

ECMO is most commonly used in NICU's (Neonatal Intensive Care Units), for newborns in pulmonary distress. It is around 75% effective in saving the newborn's life. Newborns can't be placed on ECMO if they are under 4 and a half pounds, thus ruling out the device for most premature newborns. The time limit for a newborn is usually around 21 day max.

In Adults ECMO survival rates are around 60%. In Adult VV ECMO there are reports of patients being supported for up to 42 days.

In VA ECMO, patients whose cardiac function doesn't recover sufficiently to be weaned from ECMO may be bridged to a Ventricular Assist Device (VAD) or Transplant.

See also

• Extracorporeal circulation
• Mike Richard

intensive care medicine | Medical equipment