Emboli occurrence during coronary artery bypass surgery: the influence of a new method of perfusionist blood sampling.

Peri-operative cerebral microemboli in cardiac surgery are associated with post-operative neurological complications. Cardiopulmonary bypass (CPB) and perfusionist interventions are important contributors of microemboli. In this study, we examined the influence of blood sampling by the perfusionist on the appearance of microembolic signals (MES) in an open and a closed CPB system. Fourteen patients underwent isolated coronary artery bypass grafting (CABG), using either an open or closed CPB system. Patients were monitored with transcranial Doppler (TCD) for the occurrence MES in both middle cerebral arteries (MCA) as well as in the arterial and venous lines of the CPB. In the closed system, two sampling methods were used, namely the "traditional" and the "E-line". In the latter, a shunt line was applied from the manifold to the cardiotomy reservoir). In the open system, one method of blood sampling was used. Blood sampling in an open system or in a closed system using the E-line resulted in 0.2 (+/-0.56) MES, which was significantly lower than the traditional method (72 (+/-69) MES). The use of a shunt line reduces MES during blood sampling in a closed CPB system.