Study Notes: Blood Products & Clinical Uses

Composition of Blood:

• Blood = Plasma + Cells

  • Plasma: Water + Proteins (Albumin & Globulin)

    • Albumin: Small but numerous → Maintains oncotic pressure

    • Globulins:

      • Alpha & Beta globulins: Include coagulation factors

      • Gamma globulins: Immunoglobulins (antibodies)

  • Cells:

    • Red Blood Cells (RBCs)

    • White Blood Cells (WBCs)

    • Platelets

Blood Separation

• When blood is left standing or centrifuged:

  • Bottom: RBCs

  • Middle: Buffy coat (WBCs + Platelets)

  • Top: Plasma

Note: Buffy coat may appear greenish due to neutrophils.

Laboratory Separation (Centrifugation)

1. Whole blood → RBCs + Platelet-rich plasma

2. Further centrifugation → Plasma + Platelets

3. Freeze plasma →

   • Cryoprecipitate (bottom layer)

   • Cryosupernatant (top layer)

Cryoprecipitate Components

Contains:

• Fibrinogen (Factor I)

• Von Willebrand factor

• Factor VIII

• Factor XIII

Clinical Uses:

• Hemophilia A (Factor VIII deficiency)

• Von Willebrand disease

• Hypofibrinogenemia or Afibrinogenemia

• Disseminated Intravascular Coagulation (DIC)

• Reversal of excessive anticoagulant use

Contraindications:

• Do NOT use in TTP (Thrombotic Thrombocytopenic Purpura)
  → It contains vWF, which worsens the condition.

Cryosupernatant

• Low in Factor VIII and possibly vWF

• Can be used in TTP or HUS instead of cryoprecipitate.

Fresh Frozen Plasma (FFP)

Preparation:

• Plasma separated and frozen within 8 hours at –18°C.

• Contains all coagulation factors, especially Factors V and VIII.

Indications:

• Replacement of coagulation factors (e.g., hemophilia)

• Warfarin overdose (reversal)

• Antithrombin III deficiency

• TTP (plasma exchange)

• Immunoglobulin replacement (contains antibodies)

Contraindications:

• Do not use as a volume expander → Use normal saline instead.

Side Effects:

• Allergic reactions, anaphylaxis

• TACO (Transfusion Associated Circulatory Overload)

• TRALI (Transfusion Related Acute Lung Injury)

Comparison: FFP vs. PF24

Feature	FFP (Fresh Frozen Plasma)	PF24 (Plasma Frozen within 24 hrs)
Time to freeze	Within 8 hours	Within 24 hours
Factor levels	Higher in V & VIII	Lower in V & VIII

Red Blood Cell (RBC) Transfusion

• 1 unit of packed RBCs raises:

  • Hemoglobin: by 1 g/dL

  • Hematocrit: by 3%

The Rule of Three

• RBC count × 3 = Hemoglobin

• Hemoglobin × 3 = Hematocrit

• Any deviation → recheck CBC, peripheral smear, or bone marrow.

Indications:

• Anemia

• Chemotherapy-induced marrow suppression

• Hemorrhagic shock (after fluid resuscitation)

Side Effects:

• Allergic reactions, anaphylaxis

• TRALI, volume overload

• Infections (HIV, Hep B, Hep C, CMV)

Platelet Transfusion

Indications:

• Thrombocytopenia (low count)

• Thrombocytasthenia (poor function)

• Chemotherapy-related bone marrow suppression

Side Effects:

• Allergy, anaphylaxis

• Infection

• TRALI

12 Common Doctor Errors (Never Do These!)

1. Giving sulfonamides to patients allergic to sulfur drugs.

2. Giving aspirin + warfarin → fatal bleeding risk.

3. Giving tPA to a hemorrhagic stroke patient.

4. Hyperextending the neck in rheumatoid arthritis (risk of atlanto-axial subluxation).

5. Believing “pyemia = pus in blood” (it’s septic emboli, not pus).

6. Giving biologic DMARDs to a TB patient.

7. Treating volume depletion with pure water instead of saline.

8. Thinking Pneumocystis jirovecii is a protozoa (it’s a fungus).

9. Aggressively lowering BP after ischemic stroke (allow permissive hypertension).

10. Using FFP as volume expander → Use normal saline.

11. Ignoring rule of three in CBC interpretation.

12. Forgetting to match platelets and RBCs properly before transfusion.

Key Takeaways

• FFP: Replaces clotting factors.

• Cryoprecipitate: Replaces fibrinogen, vWF, Factors VIII & XIII.

• Cryosupernatant: Used for TTP/HUS (low vWF).

• RBC transfusion: Follows Rule of 3.

• Platelets: For thrombocytopenia or dysfunction.

• Normal saline is for volume expansion, not FFP.