What should be done for a patient with a low-grade fever (temperature of 100.2°F) during a blood transfusion?

Management of Low-Grade Fever During Blood Transfusion

Stop the transfusion immediately and assess the patient for signs of a serious transfusion reaction, while recognizing that a temperature of 100.2°F (37.9°C) represents a febrile non-hemolytic transfusion reaction (FNHTR) in most cases—the most common type of transfusion reaction.

Immediate Actions

Stop and Assess

• Halt the transfusion immediately and keep the IV line open with normal saline 1
• Perform rapid assessment for signs of serious transfusion reactions including hemolysis, bacterial contamination, or transfusion-associated circulatory overload (TACO) 1, 2
• Check vital signs including blood pressure, heart rate, respiratory rate, and oxygen saturation 1

Critical Differentiation Required

• Rule out hemolytic transfusion reaction: Look for hemoglobinuria, flank pain, hypotension, or signs of DIC 1
• Rule out bacterial contamination: Assess for rigors, high fever (>39°C), hypotension, or septic shock 3
• Rule out TACO: Evaluate for dyspnea, hypoxemia, pulmonary edema, or elevated jugular venous pressure—noting that fever occurs in 31.8% of TACO cases 2
• Rule out allergic reaction: Check for urticaria, pruritus, or bronchospasm (fever occurs in only 8.2% of allergic reactions) 2

Diagnostic Workup

Laboratory Evaluation

• Obtain blood cultures from the patient immediately to rule out coincidental bacteremia or sepsis 3
• Send the blood product bag and tubing for sterility testing 3
• Check direct antiglobulin test (DAT), plasma hemoglobin, and visual inspection of plasma and urine for hemolysis 1
• Recheck clerical errors and blood compatibility 1

Clinical Context Assessment

• Review patient risk factors for FNHTR: History of multiple transfusions, pregnancy history, primary hematologic disease, malignant disease, or receipt of >6 units of leukocyte-depleted RBCs 1
• Document whether fever was present before transfusion started (24.4% of febrile cases have pre-existing fever) 2

Management Based on Assessment

If FNHTR is Confirmed (Most Likely Scenario)

• Administer antipyretic medication (acetaminophen) for symptomatic relief 1
• Provide supportive care including sedation if patient has rigors 1
• Monitor temperature every 15 minutes until stable 4
• Consider resuming transfusion at slower rate once fever resolves and serious reactions are excluded 1

Temperature Management Considerations

• A temperature of 100.2°F (37.9°C) does not require aggressive cooling measures 4
• Maintain normothermia between 36-37°C (96.8-98.6°F) as the target, as temperatures above 37°C are associated with poor outcomes in critically ill patients 4
• Do not allow temperature to drop below 36°C during management, as hypothermia impairs coagulation and increases mortality 4, 5

Prevention for Future Transfusions

Prophylactic Strategies

• Leukocyte reduction of blood products significantly reduces FNHTR incidence 6, 1
• Routine prophylactic antipyretics before transfusion remain controversial and are not universally recommended 1
• Consider premedication only in patients with history of recurrent FNHTR 1

Critical Pitfalls to Avoid

• Never assume fever is benign: Always rule out life-threatening causes first, as bacterial contamination can present similarly but requires immediate broad-spectrum antibiotics 3
• Do not restart transfusion until serious reactions are excluded through appropriate workup 1
• Avoid over-aggressive cooling: The temperature of 100.2°F does not warrant active cooling measures that could induce hypothermia 4
• Remember coincidental infection: Fever during transfusion may represent concurrent bacteremia unrelated to the blood product 3