Blood transfusion reactions

Reading File

Finding Sources

Searching PubMed

"transfusion reactions" classification management

Reading File

I now have comprehensive information from multiple authoritative textbooks. Let me compose the complete answer.

Blood Transfusion Reactions

Up to 20% of all transfusions result in some adverse reaction; most are minor, but some are life-threatening. Reactions are classified as acute (within 24 hours) or delayed (days to years), and immunologic or non-immunologic.

Classification Overview

Reaction	Mechanism	Onset	Incidence
Acute hemolytic (intravascular)	ABO incompatibility → complement activation	During/immediately after	~1:110,000
Febrile nonhemolytic (FNHTR)	Cytokines / donor leukocytes	During–4 hrs post	~1:1,100
Allergic / Anaphylactic	IgE-mediated (mild) / anti-IgA (anaphylaxis)	During–1 hr post	~1:1,200
TRALI	Anti-HLA/anti-neutrophil antibodies → neutrophil activation	Within 6 hrs	1.3–3%
TACO	Volume overload	During–6 hrs post	~1:9,000
Delayed hemolytic	Anamnestic antibody rise (Rh, Kidd, Duffy)	2–21 days	~1:32,000
Septic reaction	Bacterial contamination (platelets > RBCs)	During infusion	~1:200,000–1,000,000
Transfusion-associated GvHD	Donor lymphocytes vs. immunocompromised host	4–30 days	Rare

1. Acute Hemolytic Transfusion Reaction (AHTR)

Most dangerous immunologic reaction. About 5% of ABO-incompatible transfusions are fatal; ~50% have no adverse effect.

Mechanism: Preformed recipient antibodies (most commonly IgM anti-A or anti-B) bind transfused RBC antigens → antigen-antibody complexes activate complement cascade → intravascular hemolysis → free Hb → renal tubular damage, DIC, shock.

Cause: Almost always human error — mislabeled specimens, wrong unit issued, wrong patient identified at bedside.

Signs & Symptoms:

Fever, chills/rigors
Low back pain, flank pain, abdominal pain
Flushing, anxiety, sense of impending doom
Hemoglobinuria (red/brown urine)
Tachycardia, hypotension, shock
Diffuse bleeding (DIC)
Oliguria/anuria

In anesthetized patients, unexplained hypotension, hemoglobinuria, or diffuse oozing may be the only clues.

Management:

Stop transfusion immediately
Maintain IV access; keep line open with normal saline
Notify blood bank; return unit for repeat crossmatch
Send patient blood + urine samples to blood bank
IV fluids + furosemide/mannitol to maintain urine output ≥75–100 mL/h
Alkalinize urine (prevents Hb precipitation in tubules)
Treat DIC with FFP, cryoprecipitate, platelets as needed
Supportive care: vasopressors for hemodynamic instability
Labs: CBC, creatinine, PT/PTT, fibrinogen, haptoglobin, indirect bilirubin, LDH, plasma free Hb, urine Hb; direct and indirect Coombs (DAT/IAT)

2. Febrile Nonhemolytic Transfusion Reaction (FNHTR)

Most common reaction. Incidence has decreased significantly with universal leukoreduction.

Mechanism:

RBC components: Donor leukocytes interact with recipient WBC antibodies
Platelet components: Leukocyte-derived cytokines (IL-1, IL-6, TNF-α) accumulate during storage

Definition: Temperature rise ≥1°C or temperature >38°C ± chills/rigors within 4 hours of transfusion, with no other cause.

Management:

Stop transfusion initially (cannot distinguish from AHTR)
Hemolytic workup to exclude AHTR
Acetaminophen for fever (not aspirin — platelet recipients)
If AHTR excluded, transfusion may be restarted cautiously
Future prevention: leukoreduced or pre-storage leukoreduced products

3. Allergic Transfusion Reactions

~8% are severe. Platelets are the most commonly implicated component. Anaphylaxis may occur in IgA-deficient patients who have anti-IgA antibodies.

Spectrum:

Mild: Urticaria, pruritus, flushing (no fever, no hypotension)
Severe/Anaphylactic: Stridor, bronchospasm, hoarseness, dyspnea, hypotension, GI symptoms, shock

Management:

Mild: Stop transfusion → diphenhydramine → if symptoms resolve within 30 min, may restart
Severe/Anaphylactic: Stop permanently → epinephrine (0.3–0.5 mg IM) → H1 antihistamines + corticosteroids → airway support
If anti-IgA confirmed: use IgA-deficient donor plasma, or washed RBCs/platelets

4. Transfusion-Related Acute Lung Injury (TRALI)

Leading cause of transfusion-related mortality (FDA data 2012–2016).

Mechanism: Donor anti-HLA or anti-neutrophil antibodies (mainly in multiparous female donors) → neutrophil activation in pulmonary microvasculature → noncardiogenic pulmonary edema. All blood components implicated, especially FFP.

Diagnostic criteria:

Acute onset within 6 hours of transfusion
Bilateral pulmonary infiltrates on CXR
PaO₂/FiO₂ <300 or SpO₂ <90% on room air
No evidence of circulatory overload (left atrial hypertension absent)
No pre-existing ALI before transfusion

Symptoms: Fever, dyspnea, severe hypoxia, frothy fluid from ETT in intubated patients

Management:

Supportive (supplemental O₂, mechanical ventilation for ARDS)
No diuretics (not volume overloaded — this distinguishes from TACO)
Corticosteroids are not proven beneficial
Report to blood bank; implicated donor(s) should be deferred from future donations

5. Transfusion-Associated Circulatory Overload (TACO)

Incidence ~1:9,000. Underdiagnosed and under-reported.

Risk factors: Age >70 years, positive fluid balance >3 L, >1 unit transfused in 6 hours, post-transfusion BNP >1,000 pg/mL, pre-existing cardiac or renal disease.

Symptoms: Dyspnea, orthopnea, cough, cyanosis, hypertension (key distinction from TRALI), tachycardia, elevated JVP

TRALI vs. TACO:

Feature	TRALI	TACO
Mechanism	Non-cardiogenic	Cardiogenic/volume
Blood pressure	Usually ↓	Usually ↑
BNP	Normal or mildly ↑	Markedly ↑
Response to diuretics	No	Yes
CXR	Bilateral infiltrates (non-cardiac)	Bilateral infiltrates (cardiomegaly)

Management: Diuresis (furosemide), upright positioning, oxygen, slow future transfusion rates

6. Delayed Hemolytic Transfusion Reaction (DHTR)

Mechanism: Recipient was previously sensitized (prior transfusion or pregnancy) to minor RBC antigens (Rh, Kidd, Duffy systems most common). Antibody level at time of transfusion is below detection threshold. Anamnestic response → antibody rise → extravascular hemolysis (Kupffer cells in liver/spleen) 2–21 days post-transfusion.

Presentation:

Unexplained drop in Hb 2–21 days after transfusion
Low-grade fever, mild jaundice
Hemoglobinuria (less common than AHTR)
Can mimic postoperative bleeding
Rarely fatal (extravascular, not intravascular)

Diagnosis: Positive DAT, incompatible crossmatch, elevated bilirubin/LDH, low haptoglobin

Management: Usually supportive; monitor renal function. Not preventable — pretransfusion testing cannot detect very low antibody titers.

7. Septic Transfusion Reaction

Most commonly from platelet transfusions (stored at room temperature 20–24°C for up to 7 days).

Common organisms: Staphylococcus aureus, Serratia, Yersinia enterocolitica (in RBCs stored refrigerated).

Presentation: High fever (≥38°C, rise ≥1°C), rigors, hypotension, shock, tachycardia, nausea/vomiting — during or shortly after infusion.

Management:

Stop transfusion immediately
Blood cultures (×2, aerobic and anaerobic) before starting antibiotics
Broad-spectrum antibiotics
Hemodynamic support
Send bag + tubing to blood bank for Gram stain and culture

8. Transfusion-Associated Graft-vs-Host Disease (TA-GvHD)

Rare but almost uniformly fatal (>90% mortality).

Mechanism: Immunocompetent donor T-lymphocytes engraft and attack immunocompromised host tissues (skin, gut, liver, bone marrow).

At-risk patients: Hematologic malignancy, stem cell transplant recipients, congenital immunodeficiency, neonates receiving intrauterine transfusions, patients receiving HLA-matched or directed donations from relatives.

Prevention: Gamma-irradiation of blood components before transfusion in at-risk patients.

General Principles for Any Suspected Reaction

Stop the transfusion immediately — maintain IV access with normal saline
Notify the blood bank — return the implicated unit
Check patient/unit identity (rule out mistransfusion)
Send: new sample for retype/crossmatch, DAT, hemolytic panel (CBC, LDH, bilirubin, haptoglobin, plasma free Hb), urine Hb
Do not abandon all future transfusion — once the reaction type is characterized, appropriately matched products can usually be given safely

Sources:

Tintinalli's Emergency Medicine: A Comprehensive Study Guide, Table 238-7
Goldman-Cecil Medicine, Chapter 162
Miller's Anesthesia (10e), Chapter 45

This is a shared conversation. Sign in to Orris to start your own chat.