Suspected Acute Haemolytic Transfusion Reaction with a Label Mismatch
A 32-year-old woman is admitted after postpartum haemorrhage with Hb 6.8 g/dL. Her blood group is B RhD positive, and two units of packed red cells were crossmatched. At 15 minutes into the first unit, she complains of chills and severe lower back pain. Her temperature is 38.9°C, pulse 118/min, blood pressure 90/60 mmHg and respiratory rate 26/min. The nurse notices dark red urine in the drainage bag. The unit has about 180 mL remaining. The compatibility label on the unit reads B-4471, but the bag label reads B-4479; the patient's wristband and the compatibility form both read 'B POS'. The nurse says the shift was busy and the unit was collected quickly. The blood bank's crossmatch was an immediate spin crossmatch, and no antibody screen was performed. The patient is still receiving the transfusion as the call is made to the laboratory.
1. What are the immediate bedside and laboratory actions in the first 15 minutes?
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Bedside: stop the transfusion immediately. Disconnect the blood tubing but keep the intravenous line patent with normal saline using new tubing. Do not restart the unit. Call the medical officer, check airway, breathing and circulation, record vital signs every 15 minutes, and monitor urine output and colour. Recheck the patient's wristband and the unit labels against the prescription. Return the bag, tubing and compatibility label to the blood bank; do not discard them.
Laboratory: treat this as an acute transfusion reaction. Notify the blood bank immediately. Perform a clerical check of the unit number, patient identifiers and crossmatch record; the one-digit difference between B-4471 and B-4479 is a red flag. Collect post-transfusion samples: EDTA blood for repeat ABO/Rh and direct antiglobulin test, and clotted blood for plasma free haemoglobin, bilirubin, LDH and haptoglobin. Send a fresh urine sample for haemoglobin. Repeat ABO/Rh on the pre-transfusion sample and inspect the pre- and post-transfusion plasma for haemolysis. Do not issue further units until the reaction is investigated.
2. Which samples and tests would you perform to investigate the reaction, and what would each tell you?
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Post-transfusion EDTA sample: repeat ABO and Rh typing; direct antiglobulin test (DAT); antibody screen and, if the DAT is positive, an eluate. A positive DAT with a plasma haemoglobin rise supports immune haemolysis. Repeat ABO grouping is essential because a discrepancy may reveal the wrong patient's sample or wrong unit.
Clotted sample: plasma free haemoglobin, LDH, bilirubin and haptoglobin. A rise in free haemoglobin and LDH with low haptoglobin and raised bilirubin supports intravascular haemolysis.
Urine: haemoglobinuria explains the dark red urine and supports intravascular haemolysis.
Unit bag and tubing: inspect for clots or abnormal colour; send a sample for Gram stain and culture if bacterial contamination is suspected. Also check the unit number against the compatibility label and the patient's record. A DAT-negative reaction with fever and hypotension may instead suggest febrile non-haemolytic reaction, bacterial contamination or TRALI, so the pattern of results matters. The clerical mismatch plus dark urine and back pain makes an acute haemolytic reaction the leading concern.
3. What is the most likely cause, and what reporting and quality steps are required?
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The most likely cause is ABO-incompatible transfusion due to a clerical or identification error. The bag number B-4479 does not match the compatibility label B-4471, the unit was collected in a hurry, and the crossmatch was only an immediate spin test without an antibody screen. Fever, back pain, hypotension and haemoglobinuria are classic for an acute haemolytic reaction. Immediate priorities are supportive care, maintaining renal perfusion and urine output, and stopping all further transfusions until compatibility is re-established.
Report the event as a serious adverse transfusion reaction through the hospital haemovigilance system and to the blood bank. Complete an incident form, retain all records, samples and the unit, and perform a root-cause analysis covering sample collection, labelling, compatibility testing, issue and bedside checking. Check whether other patients or units are affected. Inform the clinician and, if a donor unit is implicated, the blood centre. Corrective actions include a two-person bedside identity check, a read-back of unit numbers, mandatory antibody screening according to policy, staff retraining and an audit of transfusion practice.