Intraoperative blood salvage

Intraoperative blood salvage (IOS), also known as cell salvage, is a specific type of autologous blood transfusion. Specifically IOS is a medical procedure involving recovering blood lost during surgery and re-infusing it into the patient. It is a major form of autotransfusion. It has been used for many years and gained greater attention over time as risks associated with allogenic (separate-donor) blood transfusion have seen greater publicity and become more fully appreciated. Several medical devices have been developed to assist in salvaging the patient's own blood in the perioperative setting. The procedure is frequently used in cardiothoracic and vascular surgery, during which blood usage has traditionally been high. A greater effort to avoid adverse events due to transfusion has also increased the emphasis on blood conservation (see bloodless surgery). Providing safe blood for transfusion remains a challenge despite advances in preventing transmission of hepatitis B virus (HBV), hepatitis C virus (HCV), AIDS/HIV, HTLV-I/II, West Nile virus (WNV), syphilis, Chagas disease, Zika virus, and transfusion-transmitted bacterial infection. Human errors such as misidentifying patients and drawing blood samples from the wrong person (i.e., wrong blood in tube or WBIT) is more of a risk than transmissible diseases in many developed nations. Much more common risks of allogeneic transfusion include allergic transfusion reactions as well as febrile non-hemolytic transfusion reactions. Additional risks include transfusion related acute lung injury (TRALI), transfusion associated circulatory overload (TACO) and transfusion-associated immunomodulation. TRALI is a potentially life-threatening condition with symptoms such as dyspnea, fever, and hypotension occurring within hours of transfusion. TACO is a much more common (even with cases being underreported) potentially life-threatening condition involving respiratory compromise within hours of a transfusion.