What are the indications for platelet transfusion in patients with dengue?

Indications for Platelet Transfusion in Dengue Patients

Platelet transfusion in dengue should be reserved for patients with active bleeding or those requiring invasive procedures, not based solely on low platelet counts. Prophylactic platelet transfusions for thrombocytopenia without bleeding in dengue patients are not recommended and may be associated with adverse events 1.

Evidence-Based Transfusion Thresholds

Active Bleeding

• Platelet transfusion is indicated for patients with severe bleeding manifestations regardless of platelet count 2
• For active bleeding, a target platelet count of ≥50,000/mm³ is advised 3

Invasive Procedures

• For patients requiring invasive procedures or surgery, maintain platelet counts at 40,000-50,000/mm³ 3
• For central venous catheter placement, transfuse if platelet count is <20,000/mm³ 3
• For lumbar puncture, transfuse if platelet count is <50,000/mm³ 3

Prophylactic Transfusion

• Prophylactic platelet transfusion in dengue patients with thrombocytopenia but without bleeding is not recommended 1, 4
• A randomized controlled trial showed that prophylactic platelet transfusion was not superior to supportive care in preventing bleeding in adult dengue patients with thrombocytopenia 1
• Prophylactic transfusion may actually be associated with adverse events including urticaria, rash, anaphylaxis, transfusion-related acute lung injury, and fluid overload 1

Special Considerations

High-Risk Patients

• Consider platelet transfusion in patients with platelet counts <20,000/mm³ with additional risk factors for bleeding 2, 5:
  • Advanced age
  • Hypertension
  • Peptic ulcer disease
  • Anticoagulant use
  • Recent trauma or surgery

Monitoring Response

• If platelet transfusion is administered, a post-transfusion platelet count should be obtained to confirm that the desired platelet count has been reached 3
• Patients with poor platelet recovery may not benefit from transfusion and may actually have increased risk of bleeding if given prophylactic platelet transfusions 6

Potential Harms of Inappropriate Transfusion

• Unnecessary platelet transfusions in dengue may:
  • Delay natural platelet recovery 4
  • Increase length of hospitalization 4
  • Cause transfusion reactions 1
  • Waste limited blood bank resources 5

Practical Approach to Platelet Transfusion in Dengue

1. Assess for active bleeding:

   • If present and significant, transfuse platelets to maintain count ≥50,000/mm³ 3

2. Evaluate need for invasive procedures:

   • For major procedures, maintain platelets at 40,000-50,000/mm³ 3
   • For minor procedures, thresholds vary (20,000-50,000/mm³) based on procedure type 3

3. For patients without bleeding:

   • Avoid prophylactic transfusion based solely on platelet count 1, 4
   • Focus on supportive care including adequate hydration and fever management 1

4. Monitor closely for signs of bleeding, especially when platelet counts are <10,000/mm³ 2

This approach aligns with evidence showing that restrictive platelet transfusion strategies based on clinical features rather than arbitrary platelet count thresholds are safe and effective for adult dengue patients 2.