Should the blood transfusion be stopped when the patient develops an isolated temperature of 38.5 °C without other signs of a transfusion reaction?

Should Blood Transfusion Be Stopped for Isolated Fever of 38.5°C?

Yes, the transfusion must be stopped immediately—isolated fever at 38.5°C during transfusion requires immediate cessation of the transfusion and cannot be assumed benign until life-threatening causes are excluded. 1, 2

Why Immediate Cessation Is Mandatory

The American Society of Anesthesiologists is unequivocal: stop the transfusion immediately at the first sign of any suspected reaction, as this single intervention can prevent progression to severe morbidity or mortality. 1, 2 While febrile non-hemolytic transfusion reaction (FNHTR) is the most common transfusion reaction and often benign, you cannot distinguish it from potentially fatal complications based on isolated fever alone. 1, 3

Critical Life-Threatening Differentials That Present With Fever

• Bacterial contamination from platelet transfusion is a leading cause of transfusion-related death and can present with isolated fever within 6 hours, particularly with platelet products. 1, 4

• Acute hemolytic transfusion reaction from ABO incompatibility can initially manifest as fever before progressing to hemodynamic collapse, renal failure, and DIC. 1, 2

• Septic transfusion reaction requires immediate broad-spectrum antibiotics after blood cultures and can be rapidly fatal if the transfusion continues. 1

The critical pitfall: General anesthesia and critical illness can mask early warning signs of serious reactions—tachycardia, hypotension, or respiratory distress may be blunted or attributed to other causes. 1, 2 Continuing the transfusion despite "just fever" is dangerous because you may miss the narrow window to prevent irreversible organ damage. 1

Immediate Management Algorithm

Step 1: Stop and Secure (First 60 seconds)

• Stop the transfusion immediately and keep the IV line open with normal saline. 1, 2
• Do not disconnect the blood tubing—you will need to send it back to the blood bank. 1

Step 2: Assess for Additional Red Flags (Next 2-3 minutes)

• Check vital signs: heart rate, blood pressure, respiratory rate, oxygen saturation, and repeat temperature. 1, 2

• Look for signs of serious reactions: 1, 4, 2

  • Hypotension (SBP <90 mmHg) or tachycardia (HR >110 bpm) → suggests hemolytic reaction, septic transfusion, or anaphylaxis
  • Respiratory distress, hypoxemia, or increased peak airway pressure → suggests TRALI or TACO
  • Dark urine, oliguria, or back/chest pain → suggests acute hemolytic reaction
  • Rash, urticaria, or bronchospasm → suggests allergic/anaphylactic reaction

• Verify patient identification and blood component labels for clerical errors—ABO incompatibility from mislabeling is the most dangerous transfusion error. 1, 4

Step 3: Notify and Investigate (Within 5-10 minutes)

• Contact the transfusion laboratory/blood bank immediately—this is legally mandated and initiates the investigation. 1, 4, 2

• Send the blood component bag with administration set back to the lab for analysis. 1, 2

• Collect post-reaction blood samples: 1, 2

  • Complete blood count
  • Direct antiglobulin test (Coombs test)
  • Repeat crossmatch
  • PT, aPTT, fibrinogen
  • Visual inspection of plasma for hemolysis
  • Blood cultures if bacterial contamination suspected

• Collect urine sample to check for hemoglobinuria. 1

Step 4: Risk-Stratify Based on Clinical Presentation

If fever is truly isolated (no hypotension, tachycardia, respiratory symptoms, or hemodynamic instability):

• This may represent FNHTR, which occurs in approximately 1.1% of transfusions with prestorage leukoreduction. 4, 3
• However, you cannot restart the transfusion before laboratory clearance, even if symptoms improve, as the reaction may worsen with continued exposure. 1
• Provide symptomatic treatment with acetaminophen 650-1000 mg orally or IV for fever control. 1

If fever occurs with any concerning features:

• Fever + hypotension/tachycardia → treat as hemolytic reaction or septic transfusion: 1, 2

  • Aggressive fluid resuscitation to maintain urine output >100 mL/hour
  • Broad-spectrum antibiotics immediately after blood cultures
  • Prepare for vasopressor support

• Fever + respiratory symptoms within 1-6 hours → consider TRALI (one of the top three causes of transfusion-related deaths): 1, 4

  • Administer high-flow oxygen
  • Provide critical care supportive measures
  • Avoid diuretics (ineffective for TRALI and may worsen outcomes)

• Fever + oliguria/dark urine → suspect hemolytic reaction with renal involvement: 1

  • Aggressive fluid resuscitation
  • Monitor urine output closely
  • Check for hemoglobinuria

Special Considerations

• Neutropenic patients or those on scheduled NSAIDs/acetaminophen may have masked fever—maintain high suspicion for infection even with persistent hypotension or oliguria unresponsive to IV fluids. 1

• Platelet transfusions within 6 hours carry the highest risk for bacterial contamination presenting as isolated fever—this is a leading cause of transfusion-related mortality. 1, 4

• Do not assume FNHTR until all laboratory results exclude hemolysis, bacterial contamination, and other serious causes. 1, 5

Documentation and Follow-Up

• Document all transfusions with 100% traceability—this is a legal requirement. 4
• Report the reaction to hemovigilance systems—TRALI and other serious reactions are underdiagnosed and underreported. 2
• Inform the patient's general practitioner—this removes them from the donor pool if indicated. 2

Bottom Line

You cannot safely continue a transfusion based on "just fever" at 38.5°C because life-threatening complications (bacterial contamination, acute hemolytic reaction, TRALI) can present identically in their early stages. 1, 2, 5 The risk of stopping a benign FNHTR is negligible compared to the catastrophic consequences of continuing a hemolytic or septic transfusion. 1, 6 Always stop, assess, investigate, and wait for laboratory clearance before considering resumption. 1, 2