Extracorporeal membrane oxygenation (ECMO) is a means of life support for failing patients who require extreme life-saving measures due to failure of their heart, lungs or both organs. In a patient suffering cardiac arrest, the faster circulation via cardiopulmonary resuscitation (CPR) can be instituted the better the outcome is. If an ECMO circuit needs to be built and primed it may add significant minutes to the response time. The purpose of this study is to test for any growth in primed ECMO circuits at given time intervals to prove the safety of leaving an ECMO circuit primed. This, in turn, may lead to decreased response time, with an arrest and the placement of the arresting patient on ECMO. Five ECMO circuits were set up, primed and sampled for bacterial growth at 0, 24, 48 and 72 hours and then at one-week intervals, with an end point of four weeks. No bacterial growth was found at any point during the sampling process.