Hematology: Blood Products

Pre-Transfusion Testing

Tests

  • Type: Determines ABO & Rh Type
  • Screen: Screens for Clinically Significant Preformed Antibodies
  • Crossmatch: Screens & Confirms Compatibility of the Patient & Donor Blood
    • Serologic Crossmatch: Physically Mix Patient Plasma & Donor RBC
    • Electronic Crossmatch: Electronically Compares Antibodies/Antigens of Patient & Donor

Orders

  • Type & Screen
    • Preferred if Considering Transfusion but Not Certain
    • Valid for Only 3 Days if Patient Has Been Transfused or Pregnant in the Past 3 Months – No Standard for Repeat Testing Otherwise
  • Type & Cross
    • Preferred if Intending to Transfuse

Blood Products

Whole Blood (WB)

Packed Red Blood Cells (PRBC)

  • Processing Modifications:
    • Leukoreduction – Removes Leukocytes
    • Irradiation – Subject to 2,500 cGy Radiation Causing Lymphocyte Inactivation
    • Washed – Washed with Saline to Decrease/Eliminate Any Residual Plasma or Platelets
    • Volume-Reduced – Volume Decreased by Centrifuge Just Prior to Transfusion
    • CMV-Negative – Tests for CMV Before Transfusion
  • Effects of Storage:
    • ATP Depletion
    • Membrane Changes & Loss of Deformability
    • Decreased 2,3-DPG (Left Shift/Increased O2 Affinity)
    • Increased Potassium (Leaks from Cells into the Fluid)
    • Oxidative Damage to Proteins & Lipids
    • *No Difference in Outcomes Between “Fresh” PRBC Over “Standard Issue” PRBC
  • Transfusion Thresholds:
  • Expected Effect:
    • 1U (200 cc) PRBC = Raise Hgb by 1.0-1.1 g/dL
    • Equilibration Timing: Generally No Difference Seen Between 15-Minutes, 1-Hour, 6-Hour & 24-Hour Post-Transfusion Draws
  • Volume: 250-300 cc

Platelets

  • Dosing:
    • Random Donor Platelets (RDP) – Single Unit Gained for Every Unit of Blood Donated
      • Platelet Yield is Insufficient to Raise Recipient Platelet Count
    • Pooled Platelets (Platelet Concentrates/“6-Pack’) – Pooling of 4-6 Units of RDP
      • Generally the Most Commonly Transfused Format
    • Single Donor (Apheresis) Platelets – Selective Removal of Platelets from a Single Donor by Apheresis
      • Platelet Yield is Equivalent to Pooled Platelets
  • Transfusion Thresholds:
  • Expected Effect:
    • Single Unit RDP = Raise Plt 5,000-10,000
    • Pooled Platelets (6-Pack) = Raise Plt 30,000-60,000
  • Volume: 350-400 cc (For Pooled Platelets/6-Pack)

Plasma

  • Forms:
    • Fresh Frozen Plasma (FFP)
      • Plasma is Frozen within 8 Hours of Collection
      • Must Be Thawed Prior to Use
      • Freezing Increases Storage Time (Up to One Year)
    • Plasma Frozen within 24 Hours After Phlebectomy (PF24)
      • Plasma is Frozen Between 8-24 Hours After Collection
      • Must Be Thawed Prior to Use
      • Most Commonly Used in the U.S. (Generally Given Even When Ordering FFP)
    • Freeze-Dried Plasma (FDP)
      • Can Be Stored at Room Temperature Before Reconstitution
  • Contents:
    • High Levels of All Factors
    • Fibrinogen (400-900 mg)
    • Physiologic Anticoagulants:
      • Protein C & Protein S
      • Antithrombin-III
      • Tissue Factor Pathway Inhibitor
    • Plasma Proteins/Albumin
  • Inherent INR of FFP: Up to 1.3
    • FFP will Not Reliably Get INR Under 1.6-1.85
    • Often Quoted as “The INR of FFP is 1.6” is a Misunderstanding
  • Volume: 200-250 cc

Cryoprecipitate (Cryo)

  • Product Derived from Plasma
  • Contents: Mn
    • Fibrinogen (150-250 mg Per Unit)
    • Factor VIII
    • von Willebrand Factor
  • Dosing:
    • Single-Unit
    • “Pools” – Generally 5 Units Given Together
      • Generally Dosed as 1-2 5-Unit Pools
  • Volume: 10-20 cc/Unit (50-100 cc/Pool)
  • Expected Effect: Increase Plasma Fibrinogen 7-10 mg/dL Per Unit

Prothrombin Complex Concentrate (PCC)

  • Product Derived from Plasma
  • Contents:
    • Factor II
    • Factor VII (Variable Levels)
    • Factor IX
    • Factor X
    • Physiologic Anticoagulants:
      • Protein C & Protein S
      • Antithrombin-III
    • *Doses Equivalent to 8-16 Units of FFP
  • Forms:
    • 3-Factor PCC: Low Levels of Factor VII
    • 4-Factor PCC (Kcentra): High Levels of Factor VII
    • Activated PCC: Similar to 4-Factor PCC with Activated Factor VII (VIIa)
      • Factor Eight Inhibitor Bypassing Activity (FEIBA)
  • Comparison to FFP:
    • More Rapid INR Correction Than FFP
      • Onset < 15 Minutes (FFP 13-48 Hours)
    • Does Not Need to Thaw
    • Smaller Volume than FFP
    • Increased Risk of Venous Thromboembolism
    • Significantly More Expensive
  • Volume: 1-2 cc/kg

Recombinant Factor VIIa

  • Contents: Recombinant Factor VIIa (rFVIIa)
  • Rapid INR Correction (Onset < 15 Minutes)
  • Increased Risk of Venous Thromboembolism
  • May Be the Only Option with Religious Objection to Blood Products (Jehovah Witness)
    • Manufactured Using DNA Biotechnology

Transfusion Reactions

Transfusion Reactions

Mnemonics

Contents of Cryoprecipitate

  • “FRI-o-precipit-EIGHT” – Cryo Has Fibrinogen & Factor VIII