Platelet Transfusion in Dengue
Platelet transfusion in dengue patients should be restricted to cases with severe bleeding, patients requiring invasive procedures, or those with platelet counts <5 × 10^9/L, as prophylactic transfusion has not been shown to reduce clinical bleeding and may increase adverse events. 1, 2
Recommendations Based on Clinical Scenarios
Severe Bleeding
- Transfuse platelets to achieve counts >50 × 10^9/L in patients with severe bleeding 1
- Clinical bleeding rather than platelet count alone should guide transfusion decisions 2
Invasive Procedures
- For patients requiring invasive procedures (e.g., surgery, lumbar puncture), transfuse platelets to achieve counts >50 × 10^9/L 1
- Ensure post-transfusion platelet count confirms adequate levels before proceeding with the procedure 3
Severe Thrombocytopenia Without Bleeding
- For patients with platelet counts <5 × 10^9/L without bleeding, platelet transfusion may be considered 1
- For patients with platelet counts between 5-20 × 10^9/L, transfusion should only be considered if additional risk factors are present (e.g., hypertension, peptic ulcer disease, use of anticoagulants) 1, 4
- Patients with platelet counts >20 × 10^9/L without bleeding do not require prophylactic platelet transfusion 2, 4
Evidence Against Routine Prophylactic Transfusion
- A randomized clinical trial demonstrated that prophylactic platelet transfusion in adult dengue patients with platelet counts ≤20 × 10^9/L without persistent mild bleeding or severe bleeding was not superior to supportive care in preventing bleeding (21% vs 26%, p=0.16) 2
- Prophylactic platelet transfusion was associated with higher rates of adverse events (6.26% vs 0.81%, p=0.0064), including urticaria, rash, pruritus, chest pain, anaphylaxis, transfusion-related acute lung injury, and fluid overload 2
- Poor platelet recovery after transfusion is common in dengue, and patients with poor recovery may actually have increased risk of bleeding if given prophylactic platelet transfusion (OR 2.34,95% CI 1.18-4.63) 5
Predictors of Poor Platelet Recovery
- Older age, lower white cell count, and earlier day of illness at presentation are significant predictors of poor platelet recovery 5
- Patients with poor platelet recovery tend to have longer hospitalizations 5
Management of Patients on Antiplatelet Therapy
- Temporary discontinuation of antiplatelet therapy in dengue patients with thrombocytopenia does not result in higher rates of major adverse cardiac and cerebrovascular events 6
- Continuation of antiplatelet therapy does not result in significantly higher rates of bleeding or need for transfusion 6
- Decision to continue or discontinue antiplatelet therapy should be based on individual bleeding risk versus thrombotic risk 6
Practical Considerations
- The median time from fever onset to platelet transfusion is typically around 6 days 1
- The median platelet yield after transfusion is approximately +12.4% 1
- A standard dose of platelets is 3-4 × 10^11 platelets (single apheresis unit or 4-6 pooled whole blood-derived concentrates) 7
- Platelet recovery in dengue typically occurs during the second week after fever onset, regardless of transfusion 1
Common Pitfalls to Avoid
- Unnecessary platelet transfusions based solely on platelet count without considering clinical bleeding 2, 4
- Failure to recognize that prophylactic transfusion may increase risk of adverse events without clinical benefit 2
- Overreliance on platelet counts without considering the overall clinical picture and phase of illness 5, 1
- Not accounting for the risk of alloimmunization with repeated platelet transfusions 7
Remember that supportive care including adequate hydration, fever control, and close monitoring remains the cornerstone of dengue management, with platelet transfusion reserved for specific indications 1, 2.