18 Principles of extracorporeal life support (ECLS)

Based on the principle of cardiopulmonary bypass (CPB), short-term circulatory support was developed to supplement cardiac and/or respiratory failure. Extra Corporeal Life Support (ECLS) involve the use of mechanical devices to temporarily support heart or lung function during cardiopulmonary failure, leading to organ recovery or replacement. Though the circuitry setup configurations represented by the different techniques are closely related, extracorporeal membrane oxygenation (ECMO) aims to supplement the failing lungs, while extracorporeal life support (ECLS) aims to support the failing heart. ECMO primarily affect oxygenation and decarboxylation of blood, while ECLS has a circulatory and a respiratory effect. The cannulation sites will essentially distinguish these two types of assistance. Venovenous ECMO (VV-ECMO) is used for respiratory failure only while venoarterial ECMO (VA-ECMO) is used for ECLS to provide support for heart failure or cardiopulmonary failure. VV-ECMO is mainly implemented in patients with severe acute respiratory distress syndrome (ARDS) unresponsive to conventional medical treatment while the most frequent indication for VA-ECMO is represented by causes of cardiogenic shock refractory to medical therapies. This lecture will provide the audience with a basic understanding of various components of the extracorporeal circuit as well as techniques of both VV and VA-ECMO.