Transfusion reactions, TRALI and TACO
Stem
A 79-year-old woman, 60 kg, with heart failure (ejection fraction 35%) and stage 3 chronic kidney disease is having a hip hemiarthroplasty under general anesthesia. She has received 2.5 L of crystalloid. Her hemoglobin was 7.2 g/dL, so two units of red cells were given over 40 minutes. Shortly after the second unit, SpO2 falls from 98% to 88% on FiO2 0.5, peak airway pressure rises, pink frothy fluid appears in the tube, and blood pressure is 174/92 with a heart rate of 112.
Question
What is your differential, and how will you manage her?
Ideal answer
HeadlineA transfusion reaction until proven otherwise, most likely circulatory overload. I stop the transfusion, keep the line open and recheck the unit against her identity.
- 100% oxygen, PEEP, suction the tube, because edema fluid is flooding her alveoli and airway.
- Differential: overload, TRALI, acute hemolysis, anaphylaxis. She fits overload best: heart failure, kidney disease, positive balance, two quick units, hypertensive rather than hypotensive.1
- BNP, chest film, arterial gas, hemolysis labs, echo: a full, poorly contracting left ventricle supports overload; an underfilled, vigorous heart and fever point to TRALI.2
- Overload: loop diuretic, head up when possible, no more fluid.1
- Report every suspected reaction to the blood bank, because TRALI needs the donor investigated;2 ICU, and any further blood slowly with diuresis.1
Breaking down the answer
- Unit check first — a clerical error causing an acute hemolytic reaction is the one diagnosis that worsens with every milliliter; it is defined within 24 hours of transfusion.3
- Definition windows — TRALI begins during or within 6 hours with PaO2/FiO2 300 or less, bilateral infiltrates and no left atrial hypertension; TACO is three or more new features within 12 hours: pulmonary edema, respiratory distress, raised BNP, cardiovascular change, fluid overload.3
- Bedside separation — TACO brings distended neck veins and a widened pulse pressure;1 TRALI brings hypotension, transient leukopenia and a normal occlusion pressure.2 This is judgment under pressure.
- Treatments diverge — TACO: stop, diuretics, oxygen.1 TRALI: stop, supportive oxygenation and low tidal volume ventilation as in ARDS; there is no specific therapy.2
- Who is at risk — TACO follows positive fluid balance, heart failure, renal failure, hemorrhagic shock and multiple products;1 TRALI follows plasma-rich components from multiparous female donors with HLA or HNA antibodies.2
Follow-up question
Twenty minutes after 40 mg of furosemide, her temperature is 38.6 °C, blood pressure 78/40, and echo shows a small, hyperdynamic left ventricle. The chest film shows bilateral infiltrates.
What now?
Follow-up answer
HeadlineThis has turned into TRALI, or TRALI on overload, and the diuretic has likely left her underfilled. I tell the team: diagnosis changed, diuresis stops.
A septic or hemolytic cause of fever and hypotension stays on the list. I restore preload carefully with small fluid boluses guided by echo and support pressure with a vasopressor. I ventilate with a low tidal volume by predicted body weight and enough PEEP for an acceptable saturation.2 I call the blood bank so the donors are screened for leukocyte antibodies.2 I reassess with gases, echo and the chest film, and tell the family she should improve over 2 to 4 days but needs close watching for 48 to 96 hours.2
Pitfalls that cost points
- Treating every post-transfusion pulmonary edema with diuretics.
- Omitting the hemolytic reaction and the identity check from the differential.
Rapid-fire
Q: Which reaction causes the most transfusion deaths? A: In FDA data from 2014 to 2018, TACO caused the largest share, 32%;1 TRALI is also a leading cause.2
Q: How common is TACO? A: About 1–8% of transfused patients, and it is underrecognized.1
Q: Which products carry the highest TRALI risk? A: Plasma-containing components and whole-blood platelets, about 1 in 2,000 plasma units versus 1 in 5,000 red cell units.2
Q: How is TRALI prevented? A: Male-donor plasma and antibody screening of female donors.2
Q: What defines a febrile nonhemolytic reaction? A: Fever of at least 38 °C with a rise of at least 1 °C within 4 hours, with chills or rigors.3
Numbers to know
| Item | Value |
|---|---|
| TRALI onset | During or within 6 h3 |
| TACO window | Within 12 h3 |
| Acute hemolytic reaction | Within 24 h3 |
| TRALI oxygenation | PaO2/FiO2 300 or less3 |
| TRALI mortality | More than 12%2 |
| TACO incidence | 1–8% of transfused patients1 |
Links
- Massive hemorrhage and transfusion, anaphylaxis, ARDS and lung-protective ventilation, Heart failure and reduced ejection fraction, Fluid management: crystalloid, colloid, goal-directed
- CDC NHSN Hemovigilance Module Protocol (2026)
Sources
- 1.Transfusion-associated circulatory overload · PathologyOutlines.com · pathologyoutlines.comChambers T, Virk M; cites FDA fatality data 2014-2018.
- 2.Transfusion-Related Acute Lung Injury (StatPearls) · StatPearls Publishing · statpearls.com
- 3.NHSN Biovigilance Component, Hemovigilance Module Surveillance Protocol v3.0 · CDC, 2026 · cdc.govCase definitions: AHTR Table 4, TACO Table 5, TRALI Table 6; FNHTR and allergic in archived Section 6.
Facts on this page were checked against these sources on Oct 15, 2026. Guidelines change; confirm doses against current institutional protocols.