Perioperative Blood Transfusion

Abstract

The use of donor (allogeneic) blood products has been vital to the development of modern surgical and anaesthetic practice. The National Blood Service supplies approximately 2.2 million units of blood products to hospitals each year. The risk of infections transmitted by blood products has caused major concern over the past twenty years. Blood transfusion today is safer than ever with regard to infective risk, but is still associated with many problems, which may adversely affect patient outcome. The prevalence of administrative errors leading to adverse patient outcome has been highlighted by haemovigilance systems such as the Serious Hazards of Transfusion (SHOT) reporting system and evidence for immunosuppression associated with transfusion has accumulated. The introduction of more sophisticated testing in order to improve the safety of donor blood has increased the cost of blood components. In addition, an increasingly elderly population and more ambitious surgery are projected to lead to an increased demand for blood products. This raises the possibility that future demand for donor blood may outstrip supply. It is for these reasons that there is a growing awareness of the need to use this valuable resource more sensibly. The aim of this review is to discuss the pivotal efficacy data and safety issues related to transfusion of red cell and haemostatic component therapies. By highlighting not only the evidence on which much of current practice is based, but also areas for concern regarding safety, the objective is to help the clinician understand the basis for strategies to minimize inappropriate use of blood and blood products. Donor blood is collected into an additive solution containing citrate that chelates calcium ions to prevent coagulation. The whole blood is now processed into various components, but typically red cell and platelet concentrates, frozen plasma and cryoprecipitate. The composition of these factors is outlined in Figure 1.