What are the signs and symptoms that indicate a transfusion reaction?

Signs and Symptoms of Transfusion Reactions

Stop the transfusion immediately at the first sign of any suspected reaction—this single intervention is the most critical action to prevent progression to severe morbidity or mortality. 1

Cardiovascular and Hemodynamic Signs

• Tachycardia (heart rate >110 bpm) is one of the most common early warning signs across all transfusion reaction types and should prompt immediate cessation of transfusion 1
• Hypotension (systolic blood pressure <90 mmHg) suggests serious reactions including acute hemolytic reaction, septic transfusion, anaphylaxis, or TRALI 1
• Bradycardia can occur specifically in anaphylactic transfusion reactions and requires immediate epinephrine administration 1
• Hypertension combined with tachycardia and respiratory distress indicates transfusion-associated circulatory overload (TACO), now the most common cause of transfusion-related mortality 1

Respiratory Manifestations

• Respiratory distress occurring within hours of transfusion distinguishes both TACO and TRALI, with TACO characterized by fluid overload and cardiovascular changes, while TRALI presents with non-cardiogenic pulmonary edema 1
• Dyspnea and hypoxemia appearing 1-2 hours after transfusion are key features of TRALI, often accompanied by fluid in the endotracheal tube 1
• Wheezing during transfusion suggests anaphylaxis or severe allergic reaction requiring urgent epinephrine administration 2
• Acute or worsening respiratory compromise with pulmonary edema occurring during or up to 12 hours after transfusion indicates TACO 1

Fever and Temperature Changes

• Fever occurring during or within 6 hours of transfusion, especially with platelet components, may indicate bacterial contamination—a leading cause of transfusion-related death 1, 3
• Fever with hypotension, tachycardia, or hemodynamic instability should be treated as a serious transfusion reaction, possibly indicating hemolytic reaction or bacterial contamination 3
• Low-grade fever alone may represent a febrile non-hemolytic transfusion reaction, estimated at 1.1% with prestorage leukoreduction 4

Dermatologic and Allergic Signs

• Rash or urticaria signals an allergic reaction and should trigger immediate transfusion cessation 1
• Hives and itching occurred in 41.4% of documented minor adverse reactions in one cancer patient cohort 5
• Severe urticaria combined with bronchospasm and hypotension indicates anaphylaxis requiring immediate epinephrine 2

Pain Symptoms

• Back pain or chest tightness are critical warning signs that may indicate an acute hemolytic transfusion reaction and mandate immediate halt of transfusion 1
• Chest pain combined with respiratory distress can indicate TACO or TRALI 1

Renal and Urinary Signs

• Oliguria or dark urine suggests hemolytic reaction with renal involvement and requires aggressive fluid resuscitation to maintain urine output >100 mL/hour 3
• Hemoglobinuria detected on urine analysis confirms intravascular hemolysis 1

Gastrointestinal Symptoms

• Nausea and vomiting can accompany transfusion reactions, documented in 1.7% of minor reactions 5
• An urge to void may be a premonitory symptom before a reaction becomes clinically apparent 1

Neurologic and Behavioral Changes

• Patients reporting vague sensations such as feeling "odd," "uncomfortable," or restless should trigger immediate vital sign assessment, as these are premonitory symptoms 1
• Behavioral changes can be signs of life-threatening complications including TACO, TRALI, or acute hemolytic reaction and should never be assumed to be purely psychiatric 1
• Headaches and nonspecific mild pains occurred in 19% of documented minor reactions 5

Timing Considerations

• The first 10 minutes of infusion are critical—immediate reactions typically occur within the first minute 1
• TRALI signs and symptoms appear 1-2 hours after transfusion 1
• TACO occurs during or up to 12 hours after transfusion 1
• Delayed reactions can occur days to weeks after transfusion 6

Critical Monitoring Parameters

• Obtain baseline vital signs pre-transfusion including heart rate, blood pressure, temperature, and respiratory rate 1
• Reassess vital signs 15 minutes after starting transfusion (critical early detection window) 1
• Monitor at completion and 15 minutes post-transfusion to detect delayed reactions 1
• Assess level of consciousness during any suspected reaction to detect early neurologic compromise 1

Common Pitfalls

• General anesthesia and critical illness can mask early signs of serious reactions, so do not continue transfusion despite "just fever" 3
• In neutropenic patients, fever may be masked by scheduled NSAIDs or acetaminophen, so maintain high suspicion even with isolated hypotension or oliguria 3
• Minor reactions are frequently underreported, with one study showing 46.6% of reactions were not reported to transfusion services 5