Transfusion Practice and Patient Blood Management
Indications and thresholds
Restrictive practice dominates current guidance: hemoglobin 7 g/dL for most stable hospitalized adults, 7–8 g/dL for cardiac and orthopedic surgery, and about 8 g/dL for acute myocardial infarction or symptomatic coronary disease. Stable, non-bleeding adults receive single-unit RBC transfusions with reassessment, not two-unit 'top-ups.' Plasma is dosed 10–15 mL/kg for coagulopathic bleeding or before an invasive procedure; it is not a volume expander. Prophylactic platelets are typically given below 10 × 10^9/L, below 50 × 10^9/L before most invasive procedures, and below 100 × 10^9/L for CNS or ophthalmic surgery. Cryoprecipitate dosing is roughly 1 unit per 10 kg, often a pool of five.
Complications to distinguish
TACO is the most frequently reported serious reaction: dyspnea, hypertension, positive fluid balance, elevated BNP, treated with diuretics. TRALI occurs within 6 hours with hypoxemia and bilateral infiltrates but no volume overload, often mediated by donor HLA or HNA antibodies. Acute hemolytic reactions present with fever, chills, flank pain, hemoglobinuria and DIC - stop the transfusion, recheck identification, run a DAT, plasma free hemoglobin and urine hemoglobin. Delayed hemolytic reactions appear 3–14 days later with a falling hemoglobin and a newly positive DAT. Also know FNHTR, anaphylaxis (IgA deficiency, haptoglobin deficiency), TA-GVHD, hyperkalemia and iron overload.
Traps
Routine premedication before transfusion is not supported. Do not confuse a delayed serologic reaction (antibody only, no hemolysis) with a delayed hemolytic reaction.
Worked example
A normovolemic 70 kg adult with hemoglobin 6.8 g/dL and no bleeding: order one unit of RBCs and reassess. One unit raises adult hemoglobin by about 1 g/dL (hematocrit about 3%).