What are the potential complications associated with blood transfusions and how can they be prevented or managed in patients with a history of previous transfusions or allergies?

Blood Transfusion-Associated Complications: Prevention and Management

Immediate Life-Threatening Complications

The two most critical acute complications requiring immediate recognition are Transfusion-Associated Circulatory Overload (TACO) and Transfusion-Related Acute Lung Injury (TRALI), both presenting with respiratory distress within hours of transfusion but requiring opposite management strategies. 1

TACO (Transfusion-Associated Circulatory Overload)

• Now the leading cause of transfusion-related mortality, occurring during or up to 12 hours post-transfusion 1
• Presents with acute respiratory compromise, pulmonary edema, cardiovascular changes (hypertension, tachycardia), and evidence of fluid overload 1
• High-risk patients: age >70 years, non-bleeding patients, heart failure, renal failure, hypoalbuminemia 1
• Management: Immediate cessation of transfusion, diuretic therapy, oxygen support 1
• Prevention: Body weight-based dosing, slow transfusion rates, close monitoring of vital signs and fluid balance 1

TRALI (Transfusion-Related Acute Lung Injury)

• Presents with non-cardiogenic pulmonary edema 1-6 hours after transfusion 1, 2
• Key features: hypoxemia, fever, dyspnea, fluid in endotracheal tube 1
• Caused by donor leukocyte antibodies (HLA class I, II, or granulocyte-specific) interacting with recipient neutrophils 1
• Management: Immediate cessation of transfusion, critical care supportive measures, oxygen therapy—avoid diuretics (ineffective and potentially harmful) 1, 2
• Prevention: Male-only plasma donors (multiparous women have significantly higher anti-HLA antibodies), screening donors for leukocyte antibodies 1

Critical distinction: TACO requires diuretics; TRALI is worsened by diuretics. 1, 2

Acute Hemolytic Transfusion Reactions

Stop transfusion immediately at first sign of any suspected reaction—this single intervention prevents progression to severe morbidity or mortality. 1, 2

Clinical Presentation

• Hypotension, tachycardia, hemoglobinuria, microvascular bleeding 2
• Back pain, chest tightness, fever (may be masked under general anesthesia) 1, 2
• Most reactions occur within the first minute of infusion 1

Immediate Management Protocol

1. Stop transfusion immediately and maintain IV access with normal saline 1, 2
2. Administer 100% high-flow oxygen 2
3. Monitor vital signs every 5-15 minutes (heart rate, blood pressure, temperature, respiratory rate, oxygen saturation) 1, 2
4. Aggressive fluid resuscitation with normal saline or lactated Ringer's to maintain MAP >65-70 mmHg 2
5. Double-check patient identification and blood component compatibility for clerical errors 2

Essential Laboratory Workup

• Complete blood count, direct antiglobulin test (Coombs), repeat crossmatch 1, 2
• PT, aPTT, Clauss fibrinogen 1, 2
• Visual inspection of plasma for hemolysis 1, 2
• Urine analysis for hemoglobinuria 2
• Blood cultures if bacterial contamination suspected 2

Allergic and Anaphylactic Reactions

Mild-Moderate Allergic Reactions

• Urticaria, rash, pruritus without respiratory or hemodynamic compromise 1
• Management: Stop transfusion, administer antihistamines, consider hydrocortisone 100-500 mg IV and famotidine 20 mg IV 1
• Prevention for future transfusions: Consider washed blood products 3

Anaphylaxis

• Hypotension with bronchospasm, urticaria, or cardiovascular collapse 2
• Management:
  • Epinephrine 0.3 mg IM into anterolateral mid-thigh immediately; may repeat once 1
  • Call emergency services/resuscitation team 1
  • Recline patient flat if hypotensive, normal saline bolus 1000-2000 mL 1
• Send mast cell tryptase levels at three time points if anaphylaxis suspected 2

Bacterial Contamination

• Fever with hypotension within 6 hours, particularly with platelet transfusion (highest risk due to room temperature storage) 2
• Management: Immediate blood cultures from patient and blood bag, broad-spectrum antibiotics 2, 3
• Can present similarly to TACO and TRALI—maintain high index of suspicion 1

Alloimmunization and Delayed Hemolytic Reactions

For patients with sickle cell disease or history of multiple transfusions, prophylactic extended antigen matching (Rh C, E, c, e and K) significantly reduces alloimmunization risk. 4

High-Risk Patients Requiring Immunosuppression

• Patients with alloantibodies for whom antigen-negative blood is unavailable 4
• History of multiple or life-threatening delayed hemolytic transfusion reactions 4
• Recommended therapy: IVIg, steroids, and/or rituximab before transfusion in acute need situations 4
• Shared decision-making between hematologist and transfusion medicine specialist is critical 4

Transfusion-Associated Graft-Versus-Host Disease (TA-GVHD)

Rare but usually fatal complication prevented by pretransfusion gamma irradiation (minimum 25 Gy) of blood products. 4

Mandatory Irradiation Indications

• Autologous and allogeneic stem-cell transplant recipients 4
• Blood products from partially matched family members 4
• Severe immunosuppression: Hodgkin's lymphoma, fludarabine/purine nucleoside analogs, antithymocyte globulin, alemtuzumab 4
• Note: Leukocyte depletion alone does NOT prevent TA-GVHD 4

Complications in Specific Surgical Populations

Brain Tumor Surgery

• Transfusion associated with increased risk of major/minor postoperative complications, infections, blood clots, renal failure, cardiovascular events, prolonged hospital length of stay 4
• Restrictive threshold <8 g/dL is safe, but liberal threshold (8-10 g/dL) may be indicated based on clinical judgment for symptomatic anemia or ongoing bleeding 4
• Tranexamic acid perioperatively decreases transfusion rates without increased seizures or thromboembolism 4

Subarachnoid Hemorrhage

• Liberal transfusion threshold of 10.0 g/dL recommended (higher than general critical care) 4
• Benefits of reducing cerebral ischemia and anemia may outweigh transfusion-associated complication risks 4
• Transfusion associated with increased vasospasm rates (particularly blood stored >14 days), infection, cardiovascular complications 4
• Use autologous blood <14 days old when available to minimize vasospasm 4

Monitoring Requirements

Vital signs must be checked at minimum: pre-transfusion, 15 minutes after starting, at completion, and 15 minutes post-transfusion. 1

Signs Requiring Immediate Action

• Tachycardia >110 beats/min 1
• Rash or urticaria 1
• Breathlessness or respiratory distress 1
• Back pain or chest tightness 1
• Temperature change, hypotension 1, 2

Critical Pitfalls to Avoid

1. Never restart transfusion even if symptoms improve—reaction may worsen with continued exposure 2
2. Do not assume isolated hypotension is benign—general anesthesia and critical illness mask early signs of serious reactions 2
3. Do not give diuretics empirically—contraindicated in anaphylaxis, hypovolemic states, and TRALI 2
4. Do not use albumin in trauma patients—trend toward higher mortality in trauma subgroup 2
5. Avoid over-expansion in trauma—excessive fluid may exacerbate portal pressure, impair clot formation, increase bleeding 2

Documentation and Reporting

• 100% traceability is a legal requirement—document all transfusions in patient record 1
• Contact transfusion laboratory immediately to report any reaction and initiate investigation 1
• Notify patient's general practitioner (removes them from donor pool) 1
• Report to blood bank—TRALI is underdiagnosed and underreported despite being leading cause of transfusion-related mortality 1
• Inform patients they received blood products before discharge 1

Special Considerations for Pregnant Women

• Continuous fetal monitoring essential during suspected transfusion reaction 3
• Consider amniotic fluid embolism in differential diagnosis of fever and hypotension post-transfusion 3
• Obstetric consultation required; consider delivery if maternal condition deteriorates or fetal distress develops 3
• Same immediate management principles apply: stop transfusion, maintain IV access, supportive care 3

Prevention Strategies Summary

The best prevention is avoiding unnecessary transfusions and maintaining a restrictive transfusion strategy. 4, 5

• Preoperative evaluation: review medical records, check for congenital/acquired blood disorders, previous drug exposures (e.g., aprotinin causing allergic reactions on re-exposure) 4
• Discontinue anticoagulation therapy sufficiently in advance (clopidogrel ~1 week, warfarin several days) 4
• Use electronic transfusion management systems rather than manual checking 1
• Positive patient identification with four core identifiers on wristband 1
• Visually inspect blood components for leakage, discoloration, clots, or clumps before administration 1
• Transfuse single units in non-hemorrhaging patients and reassess before additional units 1