18.2 Nonimmunologic Transfusion Reactions

18.2 Nonimmunologic Transfusion Reactions

Quick Answer: TACO is hydrostatic overload — hypertension, high BNP, cardiogenic edema, and diuretics help. TRALI is the noncardiogenic opposite (18.1). Bacterial contamination is a platelet disaster: rapid high fever and Gram-negative endotoxin shock, sometimes with a discolored bag. Physical hemolysis is DAT-negative and comes from overheating, hypotonic fluid (D5W), a small needle under pressure, or a pump. Citrate causes hypocalcemia in massive transfusion and apheresis. Stored or irradiated red cells leak potassium that can stop a neonate’s heart. Add hypothermia, iron overload, air embolism, mechanical injury, and transfusion-associated dyspnea. Report implicated units to the blood supplier and report fatalities (and required biological product deviations) to FDA/CBER.

This is V.C.2. The antibody workup in 18.1 still happens, because you cannot see “nonimmunologic” stamped on the bag. What changes is the mechanism you name after hemolysis and clerical identity are addressed.

TACO versus TRALI — learn the pair, not one orphan

Transfusion-associated circulatory overload (TACO) is too much volume too fast for that heart. The lung fills from the venous side. Blood pressure rises. The patient may have headache, orthopnea, bounding pulses, elevated JVP, an S3, and a wide pulse pressure. Chest imaging looks cardiogenic. BNP or NT-proBNP is high (or rises sharply from the patient’s baseline). Diuretics and sitting the patient up help because you are treating hydrostatic pressure, not a capillary leak.

Risk is not mysterious: small patients, elders, chronic anemia with a high-output heart, renal failure, already-positive fluid balance, and rapid multi-unit infusion without a warmer or a pause. Prevention is slow the rate, transfuse one unit at a time, and split or titrate in the vulnerable. TACO can follow any component, including plasma given for INR cosmetics.

Put TACO next to TRALI, AHTR, and bacterial sepsis on one card. The exam loves a dyspneic, febrile, hypotensive stem and four look-alike names.

Worked scenario. An 82-year-old with CKD receives two red-cell units in 90 minutes. She sits bolt upright, BP 190/100, JVP raised, BNP triples, and she diureses 800 mL after furosemide with relief. That is TACO. A 40-year-old trauma patient who becomes hypoxic and hypotensive 2 hours after plasma, with a normal heart size and a low BNP, is TRALI until proven otherwise — and the plasma donor is investigated.

Bacterial contamination

Room-temperature platelets are the highest-risk component because 20–24 °C is a culture incubator. Gram-negative organisms (Klebsiella, Serratia, Pseudomonas, and others) dump endotoxin and produce abrupt high fever, rigors, and refractory shock. Staphylococci also contaminate skin-entry collections. Refrigerated red cells have a different villain: cold-tolerant Yersinia enterocolitica, which can bloom late in storage. Visual clues — discoloration, clots, hemolysis, bubbles — are late and insensitive. Absence of a “funny bag” does not exclude sepsis.

After you stop the transfusion, Gram stain and culture the unit and the patient. Return the bag and set. Notify the collecting facility immediately so co-components from the same donation can be quarantined. Chapter 4.2 already made bacterial-risk control (pathogen reduction, LVDS, primary-plus-secondary testing) part of the platelet definition; this section is the bedside disaster when that control fails or a unit was issued outside it.

Physical hemolysis, citrate, potassium, and cold

Physical (mechanical or osmotic) hemolysis looks like AHTR at the centrifuge — pink plasma, falling haptoglobin, hemoglobinuria — but the DAT is negative, the clerical check matches, and the antibody screen is unchanged. Causes you must name:

• Overheating (malfunctioning blood warmer, microwave, parking a unit on a radiator).
• Freezing a red-cell unit that should have stayed at 1–6 °C.
• Hypotonic infusion: piggybacking blood with D5W or sterile water, or using a hypotonic flush.
• Small-bore needle plus a pressure bag or a poorly set infusion pump shearing cells.
• Infusion with incompatible IV fluids that are not 0.9% NaCl.

Treat the hyperkalemia and the hemoglobin load; do not chase an eluate as if this were Kidd.

Hypocalcemia is citrate toxicity. Citrate in the anticoagulant binds ionized calcium (and magnesium). The liver ordinarily metabolizes it in minutes. Massive transfusion, liver failure or anhepatic liver transplant, pediatric patients, and apheresis (donor or therapeutic) overwhelm that clearance. The patient gets perioral tingling, tetany, prolonged QT, and hypotension. Give ionized calcium, not a DAT. Slow the citrate load; warm the patient so metabolism recovers.

Hyperkalemia is a storage lesion plus irradiation. Extracellular potassium rises as ATP falls; irradiation accelerates the leak. Neonates, intrauterine transfusion, and massive transfusion through a central line see that potassium bolus before the cells pick it back up. Use fresher, just-irradiated, or washed red cells when the protocol calls for it. Do not irradiate a unit days early “for convenience” and then give it as a neonatal massive-transfusion bolus.

Hypothermia from unwarmed massive transfusion worsens coagulopathy, citrate toxicity, and arrhythmia. A blood warmer on a validated setting is part of the massive-transfusion setup, not a luxury.

Iron, air, mechanical injury, and TAD

Each red-cell unit delivers on the order of 200–250 mg of elemental iron. There is no physiologic excretion pathway. Chronically transfused patients (thalassemia, sickle cell disease, myelodysplasia) accumulate iron in liver, heart, and endocrine organs. That is transfusional iron overload, not an acute reaction. Management is chelation and transfusion reduction, not a STAT DAT.

Air embolism is an administration and apheresis problem: an empty bag under pressure, a disconnected central line, or air in an apheresis circuit. Sudden dyspnea, chest pain, and cardiovascular collapse are the picture. Clamp, left-lateral head-down positioning as an emergency maneuver, and oxygen — then review how air entered the line.

Mechanical injury overlaps physical hemolysis: roller pumps, rapid infusers, and small needles. Name the device, not an antibody.

Transfusion-associated dyspnea (TAD) is respiratory distress temporally related to transfusion that does not meet criteria for TRALI, TACO, or an allergic reaction. It is a diagnosis of exclusion and a hemovigilance code, not a license to skip the workup. If you can name TACO or TRALI, do not call it TAD.

Reporting — supplier and FDA, not just the chart

A suspected hemolytic, septic, or TRALI reaction is reported to the collecting facility the same day so other components from that donation can be retrieved. Mild isolated urticaria stays local; fatalities and distributed-product problems do not.

21 CFR 606.170(b): when a complication of blood collection or transfusion is confirmed to be fatal, the collecting facility — and, if different, the facility that performed compatibility testing — must notify FDA CBER as soon as possible (telephone, fax, express mail, or electronic) and submit a written report within 7 days. That is a fatality clock, not a “when you get to it” memo.

21 CFR 606.171 requires a biological product deviation report when a distributed product may have had its safety, purity, or potency affected (wrong label released, untested unit shipped, temperature excursion that left the building). Not every bedside hive is a BPD. A released unit that should never have left quarantine is.

Exam traps. Hypertension plus high BNP plus diuretic response is TACO, not TRALI. Bacterial shock is a platelet story first. Pink plasma with a negative DAT is physical until you prove otherwise — look for D5W, heat, and needles. Citrate is calcium, not “allergy to FFP.” Irradiated stored red cells are a potassium problem for neonates. Fatalities go to FDA CBER within the ASAP / 7-day written framework, and the supplier must hear about implicated donors.