Transfusion triggers and strategies

Transfusion triggers and strategies

Transfusion triggers and strategies

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Blood Components - The Bloody Basics

  • Packed Red Blood Cells (PRBCs): ↑ O₂ capacity & tissue perfusion. 1 unit (~300mL) ↑ Hb by 1 g/dL & Hct by 3%.
  • Platelets: For active bleeding with thrombocytopenia (<50,000/μL) or dysfunction. 1 apheresis pack ↑ count by 30-60k.
  • Fresh Frozen Plasma (FFP): Replaces all clotting factors. Use for coagulopathy (INR >1.5), warfarin reversal.
  • Cryoprecipitate: Concentrated fibrinogen, vWF, Factor VIII. Use for fibrinogen <100-150 mg/dL.

⭐ FFP from an AB donor is universal because it contains no anti-A or anti-B antibodies.

Blood components after centrifugation

RBC Transfusion - Seeing Red Signals

  • Restrictive Strategy (Standard): Transfuse for Hemoglobin (Hgb) < 7 g/dL.
    • Target Hgb: 7-9 g/dL.
  • Liberal Strategy (Exceptions): Consider for Hgb < 8 g/dL in specific cases:
    • Acute Coronary Syndrome (ACS) with active ischemia.
    • Symptomatic anemia (e.g., chest pain, dyspnea).
    • Active bleeding / hemorrhagic shock.
  • Each unit of packed RBCs (pRBCs) should ↑ Hgb by ~1 g/dL and Hematocrit (Hct) by ~3%.

⭐ In stable, hospitalized patients, a restrictive transfusion threshold of 7 g/dL is associated with better outcomes compared to a liberal strategy.

Restrictive vs. Liberal Transfusion in Colorectal Surgery

Platelets & Plasma - The Clotting Crew

  • Platelets (Thrombocytes): For severe thrombocytopenia or platelet dysfunction with active bleeding.

    • Prophylactic Triggers:
      • < 10,000/μL to prevent spontaneous hemorrhage.
      • < 50,000/μL prior to most invasive procedures.
      • < 100,000/μL for neuro/ocular surgery.
    • Therapeutic: Active bleeding with platelets < 50,000/μL.
  • Fresh Frozen Plasma (FFP): Replaces all clotting factors.

    • Triggers:
      • Active bleeding with INR > 1.7.
      • Massive Transfusion Protocol (MTP): often a 1:1:1 ratio (RBC:FFP:Platelets).

⭐ FFP requires ABO compatibility. For urgent warfarin reversal, Prothrombin Complex Concentrate (PCC) is faster than FFP.

Blood components: plasma, buffy coat, and red blood cells

Massive Transfusion - Code Red Tsunami

  • Activation: For hemorrhagic shock. Defined as transfusion of >10 units pRBCs in 24 hrs, or >4 units in 1 hr.
  • Strategy: Use a balanced 1:1:1 ratio of pRBCs:FFP:Platelets to mimic whole blood.
  • Goals: Restore volume, reverse coagulopathy, and prevent the lethal triad.

Lethal Triad: MTP aims to prevent or reverse the deadly cycle of acidosis, hypothermia, and coagulopathy seen in massive hemorrhage.

Transfusion Reactions - When Good Blood Goes Bad

  • Immediate Action: Stop transfusion, maintain IV access with normal saline.
  • Common Types & Hallmarks:
    • Acute Hemolytic: Type II HSR (ABO incompatibility). Fever, flank pain, hemoglobinuria. Positive Coombs test.
    • Febrile Non-Hemolytic (FNHTR): Most common. Cytokine-mediated. Fever, chills, rigors.
    • Allergic/Anaphylactic: Type I HSR. Urticaria, pruritus. Anaphylaxis if IgA-deficient.
    • TRALI: Donor anti-leukocyte antibodies. Acute respiratory distress within 6 hours.
    • TACO: Volume overload. Dyspnea, hypertension, pulmonary edema.

⭐ Febrile Non-Hemolytic Transfusion Reaction (FNHTR) is the most frequent reaction, managed with antipyretics. Leukoreduction of blood products can prevent it.

High-Yield Points - ⚡ Biggest Takeaways

  • A restrictive transfusion strategy (trigger Hb <7 g/dL) is generally preferred for most stable, hospitalized patients.
  • Consider a higher threshold (Hb <8 g/dL) for patients with symptomatic cardiovascular disease or those undergoing cardiac/orthopedic surgery.
  • Transfuse for symptomatic anemia (e.g., chest pain, dyspnea) regardless of the absolute Hb value.
  • For massive hemorrhage, activate the Massive Transfusion Protocol (MTP) with a 1:1:1 ratio of pRBCs:FFP:Platelets.
  • Transfuse platelets if <10,000/µL or <50,000/µL before major surgery.

Practice Questions: Transfusion triggers and strategies

Test your understanding with these related questions

A 26-year-old woman is brought to the emergency department after a motor vehicle accident. She was driving on the highway when she was struck by a van. At the hospital she was conscious but was bleeding heavily from an open wound in her left leg. Pulse is 120/min and blood pressure is 96/68 mm Hg. She receives 3 L of intravenous saline and her pulse slowed to 80/min and blood pressure elevated to 116/70 mm Hg. The next morning she is found to have a hemoglobin of 6.2 g/dL. Her team decides to transfuse 1 unit of packed RBCs. Twenty minutes into the transfusion she develops a diffuse urticarial rash, wheezing, fever, and hypotension. The transfusion is immediately stopped and intramuscular epinephrine is administered. Which of the following scenarios is most consistent with this patient's reaction to the blood transfusion?

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Flashcards: Transfusion triggers and strategies

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_____ is caused by GAS and enters through trauma openings causing infection and ultimately necrotic skin with large bullae.

TAP TO REVEAL ANSWER

_____ is caused by GAS and enters through trauma openings causing infection and ultimately necrotic skin with large bullae.

Necrotizing fasciitis

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