Hematology, Oncology & Immunology · Topic 4 of 26

Blood Product Transfusion

Hematology · transfusion medicine

Blood Product Transfusion

Transfuse restrictively: red cells below Hb 7 g/dL one unit at a time, platelets below 10,000, plasma and cryoprecipitate only for bleeding with a measured deficit.

Key numbers

Transfuse red cells when Hb under 7Hb < 7 g/dL

Prophylactic platelets below 10,000plt < 10,000/mcL

Cryoprecipitate for bleeding with low fibrinogenfibrinogen < 100 mg/dL

ACS with anemia: Hb 10 may be reasonableACS: Hb ≥ 10 g/dL (2b)

One unit raises Hb about 1 g/dL+1 g/dL per unit

01 · The numberTransfuse red cells when Hb under 7

For hemodynamically stable hospitalized adults, consider red-cell transfusion when hemoglobin falls below 7 g/dL (AABB 2023, strong); clinicians may use 7.5 g/dL for cardiac surgery and 8 g/dL for orthopedic surgery or preexisting cardiovascular disease.

02 · The ruleGive one unit, then reassess

In a stable patient, transfuse a single red-cell unit and then reassess hemoglobin and symptoms before ordering more; decisions weigh symptoms, bleeding and cardiopulmonary reserve, not the number alone.

03 · The numberProphylactic platelets below 10,000

Give prophylactic platelets to nonbleeding adults with hypoproliferative thrombocytopenia (chemotherapy, allogeneic transplant) or consumptive thrombocytopenia when the count is below 10,000/mcL; higher thresholds apply before procedures.

Diagnosis & monitoring

Work-up

ACS with anemia: Hb 10 may be reasonableIn acute coronary syndrome with acute or chronic anemia and no active bleeding, transfusing to keep hemoglobin at least 10 g/dL may be reasonable (2025 ACC/AHA, class 2b), based on the MINT trial.

Hematology-oncology inpatients: also Hb 7Hospitalized adults with hematologic or oncologic disorders also follow a restrictive red-cell threshold of 7 g/dL (AABB 2023, conditional recommendation).

One unit raises Hb about 1 g/dLOne unit of packed red cells raises an average adult's hemoglobin by about 1 g/dL and hematocrit by about 3% above the pretransfusion value.

Pre-procedure thresholds: CVC 10k, LP 20k, surgery 50kTransfuse platelets before a procedure when the count is below 10,000/mcL for a compressible-site central line, 20,000 for lumbar puncture or low-risk IR, and 50,000 for high-risk IR or major non-neuraxial surgery.

Management

Orders

Plasma for bleeding with multiple factor deficits must knowGive fresh frozen plasma for bleeding with multiple factor deficits (DIC, liver failure, massive transfusion) — not for volume, mild INR elevation before procedures, or DOAC bleeding; 4F-PCC is first-line for urgent warfarin reversal.

Cryoprecipitate for bleeding with low fibrinogen must knowCryoprecipitate replaces fibrinogen: give it for bleeding with fibrinogen below 80–100 mg/dL (rarely needed above 150 mg/dL outside pregnancy); a 10-unit pool raises fibrinogen about 100 mg/dL.

Bleeding patient: keep platelets above 50,000Transfuse platelets for active bleeding with a count below 50,000/mcL, for dilutional thrombocytopenia in massive transfusion, and for bleeding on non-aspirin antiplatelet drugs despite a normal count.

Normal saline only; finish within 4 hoursInfuse through an 18-gauge or larger catheter with a standard filter; only 0.9% saline may share the line (hypotonic fluid lyses cells, lactated Ringer's calcium clots); complete each unit within 4 hours.

Bedside identity check; watch the first 15 minutesCheck the wristband, unit label and compatibility report at the bedside before starting — misidentification causes most ABO-incompatible reactions — then record vital signs and observe closely for the first 15 minutes.

Hemorrhagic shock: uncrossmatched group O red cellsIn hemorrhagic shock with no time for compatibility testing, give uncrossmatched group O red cells — Rh-negative for females of childbearing age, Rh-negative or Rh-positive for others; ABO/Rh type-specific blood takes about 10 minutes.

Slow transfusion and diuretic if TACO riskFor older adults and patients with heart failure or renal insufficiency, transfuse slowly (the blood bank can split units into aliquots) and consider a prophylactic diuretic to prevent circulatory overload.

Red flags & don'ts

Avoid harm

No platelets for ICH with count over 100,000 avoidDo not transfuse platelets for nonoperative intracranial hemorrhage when the count exceeds 100,000/mcL, even on antiplatelet drugs, or for cardiac surgery without thrombocytopenia or major bleeding.

The rules

Know these

Irradiate for transplant and blood cancersIrradiate cellular products to prevent transfusion-associated GVHD in immunocompromised recipients (hematologic cancers, stem cell transplant), donations from first-degree relatives and HLA-matched units; steroids alone are not an indication.

Leukoreduced for febrile reactions; washed for IgA deficiencyLeukoreduced units prevent recurrent febrile nonhemolytic reactions, reduce CMV transmission and HLA alloimmunization; washed red cells or IgA-deficient donor products are used for severe plasma allergy or IgA deficiency.

Plasma or cryoprecipitate?

Commonly confused

Contains	All clotting factors, unconcentrated
Main use	Bleeding with multiple factor deficits: DIC, liver failure, massive transfusion
Warfarin reversal	Only if 4F-PCC is unavailable
Volume	Large — circulatory overload risk

More detail

Reference

Show 7 reference facts

Massive transfusion = one blood volume or more in 24 hours (about 10 units in a 70-kg adult); protocols give plasma and platelets early in balanced ratios (see Massive Transfusion & Trauma Coagulopathy).

Each cryoprecipitate unit holds about 250 mg fibrinogen plus factor VIII, von Willebrand factor, factor XIII and ADAMTS13, in 3–10 times less plasma volume than FFP.

Do not give plasma for bleeding from unfractionated heparin overdose — its antithrombin can potentiate heparin; plasma is also ineffective for factor Xa inhibitor or direct thrombin inhibitor bleeding.

Platelet refractoriness (poor count increment) comes from sepsis, DIC, splenic sequestration or HLA alloimmunization; alloimmunized patients may respond to HLA- or ABO-matched platelets.

Packed red cells are stored at 1–6 °C for up to 42 days; platelets at room temperature for 5–7 days, which makes them the product most prone to bacterial contamination.

Treat iron deficiency instead of transfusing when time allows: IV iron is generally first choice for absolute iron deficiency in complex patients; red cells are not given for iron deficiency without hemodynamic instability.

Prophylactic platelet transfusion is not recommended for nonbleeding adults after autologous stem cell transplant or with aplastic anemia, or for dengue-related thrombocytopenia without major bleeding.

Pearl

Seven is the new ten: a restrictive threshold is as safe as a liberal one for most stable inpatients — and every unit carries risk.

Sources · Carson JL et al. Red Blood Cell Transfusion: 2023 AABB International Guidelines. JAMA 2023;330:1892–1902 · Merck Manual Professional — Blood Products (rev. Apr 2026) · Merck Manual Professional — Technique of Transfusion (rev. Mar 2026) · Merck Manual Professional — Blood Collection (pretransfusion testing, emergency transfusion) · Metcalf RA et al. Platelet Transfusion: 2025 AABB and ICTMG International Clinical Practice Guidelines. JAMA 2025;334:606–617 · OpenAnesthesia — Cryoprecipitate (quotes ASA: fibrinogen < 80–100 mg/dL with bleeding; 10 units raise fibrinogen ~100 mg/dL) · AABB — New ACC/AHA guidelines include transfusion strategies for ACS management (Class 2b, Hgb ≥ 10 g/dL) · Carson JL et al. Restrictive or Liberal Transfusion Strategy in Myocardial Infarction and Anemia (MINT). N Engl J Med 2023;389:2446–2456 (PMC10837004) · Merck Manual Professional — Complications of Transfusion (rev. Apr 2026) · Carson JL, Brittenham GM. How I treat anemia with red blood cell transfusion and iron. Blood 2023;142:777–785 (PMC10485845) · AABB / Choosing Wisely — Five Things Physicians and Patients Should Question (single-unit transfusion; no red cells for iron deficiency without instability) · Starter sheet built from the verified AGACNP fact map (facts reviewed 2026-10-15).