Blood transfusion in cardiac surgery: Primum non nocere

This thesis is about the possible benefits and harmfull effects of transfusing blood products during cardiac surgery. We found that when transfusing red cellls, not only the Hb level but also the relative Hb decrease is important in preventing postoperative morbidity and mortality. A selected population of jehovah's witnesses can undergo bloodless cardiac surgery we compared a sample of that population with non-Jehovah witnesses who did receive red cells and found that there was no difference between both the groups. That implies that when non-Jehovahs were treated as Jehovah witnesses the transfusion could be avoided. Often platelets are transfused at the end of cardiac surgery but the effectiveness and possible risks are still not exactly known. We analysed a population of patients who received one platelet concentrate during cardiac surgery and found that these patienst had less blood loss, but these patients stayed longer at the ICU and were longer mechanically ventilated.Also, we validated the EuroSCORE II in a dutch population and found that it outperformed its predecessor the EuroSCORE I. We also assesed whether or not a prolonged storage time of erytrocytes was associated with the formation of anti-K and found that this was not the case.