Blood comprises various components, each serving a distinct function in maintaining hemostasis and oxygen transport. Understanding the roles and appropriate use of these components is critical for anesthesia providers to ensure safe and effective transfusion practices in perioperative care.
Red Blood Cells (RBCs)
Red blood cells are the most commonly transfused blood component and are critical for oxygen delivery to tissues. Anemia, severe blood loss during surgery, and conditions that impair oxygen-carrying capacity often necessitate RBC transfusions. The goal is to restore oxygen delivery while maintaining hemodynamic stability. One unit of packed red cells holds about 300 mL at a hematocrit of 55-65% and raises an adult's hemoglobin about 1 g/dL. Red cells are refrigerated at 1-6 degrees C for up to 42 days, and during storage they develop the storage lesion: 2,3-DPG falls (shifting the oxygen-hemoglobin curve to the left), potassium and lactate accumulate, pH drops, and the cells lose deformability. These changes matter most when many older units are given quickly.
Clinical Example: In a patient with acute bleeding during surgery, RBC transfusion is indicated to restore oxygen-carrying capacity and maintain tissue perfusion. Careful monitoring of hemoglobin levels and oxygen saturation will guide the decision to transfuse.
Platelets
Platelets are essential for blood clotting and are often administered in patients with thrombocytopenia (low platelet count) or platelet dysfunction. Transfusion of platelets is common in patients undergoing major surgeries, especially those with significant blood loss or platelet dysfunction from antiplatelet drugs, uremia, or cardiopulmonary bypass. Platelets are stored at room temperature (20-24 degrees C) with continuous agitation for 5 to 7 days, which is why they carry the highest bacterial contamination risk of any component.
Clinical Example: A patient with pre-existing thrombocytopenia undergoing major abdominal surgery may require platelet transfusion to prevent excessive intraoperative bleeding. Anesthesia providers must closely monitor platelet counts and bleeding risk during the procedure.
Fresh Frozen Plasma (FFP)
FFP contains clotting factors and is used to correct coagulopathies, such as those seen in patients with liver disease, warfarin overdose, or disseminated intravascular coagulation (DIC). FFP contains all coagulation factors at roughly normal plasma concentrations. It is stored frozen for up to a year and, once thawed, kept at 1-6 degrees C for 24 hours (or up to 5 days as thawed plasma). A therapeutic dose is 10-15 mL/kg, which raises factor levels about 20-30%; smaller volumes rarely change the INR, and FFP should not be used as a volume expander. For urgent warfarin reversal, four-factor PCC is now preferred over FFP because it is faster, smaller in volume, and needs no thawing.
Clinical Example: A patient with liver cirrhosis scheduled for a liver resection presents with elevated INR and prolonged clotting times. In cirrhosis the INR overstates bleeding risk because anticoagulant proteins fall alongside the procoagulant factors, so FFP is reserved for active bleeding or a high-risk procedure rather than given to normalize the INR, and viscoelastic testing (TEG or ROTEM) guides the decision when available.
Cryoprecipitate
Cryoprecipitate is a concentrated source of clotting factors, particularly fibrinogen, factor VIII, and von Willebrand factor. Each unit holds at least 150 mg (typically about 250 mg) of fibrinogen in only 10-15 mL, so a 10-unit pool raises an adult's fibrinogen roughly 50-70 mg/dL; it also contains factor XIII and fibronectin. After thawing it is kept at room temperature and must be transfused within 4 to 6 hours. It is used to manage hypofibrinogenemia, and it is especially important in massive transfusion because fibrinogen is usually the first factor to reach a critically low level.
Clinical Example: A trauma patient experiencing massive blood loss and dilutional coagulopathy may require cryoprecipitate to restore fibrinogen levels and improve clot formation during surgery.
