Adverse Effects

Vigilance in patient ID, sample handling, compatibility testing, component selection, patient monitoring, and prompt reaction investigation are essential for minimizing all adverse effects. These effects fall into three broad categories: Immunologic reactions, Non-immunologic reactions, and Transfusion-Transmitted Diseases

Here’s a comprehensive overview:

Immunologic Reactions: The Immune System Responds

These occur when the recipient’s immune system reacts against donor blood components (or vice-versa). Timing is key (Acute: <24h; Delayed: >24h)

• Acute Reactions (<24h)
  • Acute Hemolytic (AHTR): Most feared, often ABO incompatibility (clerical error!). Rapid intravascular hemolysis via complement. Symptoms: Fever, chills, back/flank pain, hemoglobinuria, hypotension, shock, DIC. Potentially fatal
  • Febrile Non-Hemolytic (FNHTR): Most common. Due to recipient antibodies vs. donor WBCs, or cytokines in stored unit. Symptoms: Fever (≥1°C rise), chills, malaise. No hemolysis. Reduced by leukoreduction
  • Allergic (Urticarial): Common, mild. Reaction to donor plasma proteins (histamine release). Symptoms: Hives, itching. No fever
  • Anaphylactic: Rare, severe. Often in IgA-deficient patients with anti-IgA. Symptoms: Rapid onset shock, respiratory distress, angioedema, NO fever. Requires washed components for prevention
  • TRALI (Transfusion-Related Acute Lung Injury): Leading cause of transfusion death. Donor antibodies vs. recipient neutrophils -> lung capillary damage. Symptoms: Acute respiratory distress, hypoxia, bilateral pulmonary edema without circulatory overload, within 6 hours
• Delayed Reactions (>24h)
  • Delayed Hemolytic (DHTR): Anamnestic response to RBC antigens (Kidd, Duffy, Kell, Rh). Extravascular hemolysis days/weeks later. Symptoms: Falling Hgb, jaundice, fever, positive DAT. History check is key!
  • TA-GVHD (Transfusion-Associated Graft-vs-Host Disease): Rare, highly fatal. Donor T-cells attack recipient tissues (immunocompromised or related donor). Symptoms: Rash, fever, diarrhea, liver dysfunction, pancytopenia (1-2 weeks post). Prevented by irradiation
  • Post-Transfusion Purpura (PTP): Rare. Abrupt severe thrombocytopenia (~1 week post) due to platelet alloantibody destroying donor and patient platelets
  • Alloimmunization: Development of antibodies to RBC, platelet, or HLA antigens. Risks future DHTR, HDFN, platelet refractoriness

Non-Immunologic Reactions: Physical, Chemical, or Volume Issues

Caused by the component’s properties or the infusion process itself

• Transfusion-Associated Circulatory Overload (TACO): Common, especially in susceptible patients (elderly, cardiac/renal disease). Infused volume exceeds capacity. Symptoms: Respiratory distress, hypertension, tachycardia, jugular venous distension, pulmonary edema. Manage with slower infusion, diuretics
• Bacterial Contamination (Sepsis): Most common infectious risk now, esp. with room-temp stored platelets. Rapid onset fever, chills, shock. Life-threatening. Requires immediate stop, cultures, antibiotics
• Hypothermia: From rapid infusion of cold blood. Can worsen acidosis, coagulopathy. Prevent with blood warmers for massive/rapid infusions
• Citrate Toxicity / Hypocalcemia: Citrate anticoagulant binds ionized calcium. Risk with massive/rapid transfusion or liver failure. Symptoms: Paresthesias, tetany, hypotension. Monitor ionized Ca++, give calcium PRN
• Hyperkalemia: Potassium leaks from RBCs during storage. Risk with rapid infusion of older units, neonates, renal failure. Symptoms: Muscle weakness, cardiac arrhythmias. Use fresh/washed cells for high-risk patients
• Physical Hemolysis: RBC damage from improper storage (temp), handling (pressure), or mixing with non-isotonic IV fluids. Can mimic hemolytic reaction (DAT negative)
• Iron Overload (Hemosiderosis): Chronic complication in long-term transfused patients. Iron deposition damages organs (heart, liver, endocrine). Requires iron chelation therapy

Transfusion-Transmitted Diseases (TTDs): Infectious Agents

Risk is extremely low due to rigorous donor screening and testing, but not zero (“window period”)

• Viruses: HIV, HCV, HBV (risk minimized by NAT), HTLV, CMV (risk for immunocompromised; use CMV-neg or leukoreduced), WNV, Zika
• Bacteria: See Sepsis above
• Parasites: Malaria, Babesia, Chagas (risk depends on geography/travel; screening/testing helps)
• Prions: vCJD (extremely rare; risk based on geographic deferral)
• Prevention: Multi-layered approach: donor screening questionnaires, deferrals, lab testing (serology + NAT), bacterial detection (platelets), pathogen reduction (plasma/platelets)