Blood products. Main principles of transfusion

1. Big picture

Transfusion is component therapy, not “giving blood because the number is low.” The key clinical question is:

What is missing: oxygen-carrying capacity, platelets, coagulation factors, or fibrinogen?

Blood transfusion is essentially a tissue transplantation with possible serious complications, so every unit must have a clear indication, compatibility check, monitoring, and reassessment. The question file emphasizes that there is no universal hemoglobin trigger for all patients; transfusion decisions depend on oxygen demand, cardiac output, oxygen saturation, comorbidities, and clinical context. It also states that transfusion is seldom indicated above Hb 10 g/dL and always indicated below Hb 6 g/dL, while Hb 6–10 g/dL needs individual judgment.

Core exam logic:

Anemia with poor oxygen delivery → red blood cells
Thrombocytopenia/platelet dysfunction with bleeding risk → platelets
Multiple coagulation factor deficiency → fresh frozen plasma
Low fibrinogen → cryoprecipitate/fibrinogen concentrate
Warfarin/coumarin major bleeding → PCC ± vitamin K ± FFP

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