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

Platelet Transfusion in Dengue: Evidence-Based Recommendations

Prophylactic platelet transfusion should NOT be given to dengue patients based solely on low platelet counts, as it does not prevent bleeding and may actually cause harm by delaying platelet recovery and increasing adverse events. 1, 2

Key Principle: Dengue is NOT a Hypoproliferative Thrombocytopenia

The fundamental error in dengue management is applying cancer/leukemia transfusion guidelines (which use a 10,000/μL prophylactic threshold) to dengue patients. 1 Dengue causes thrombocytopenia through increased platelet destruction, not impaired production, making prophylactic transfusion relatively contraindicated. 1, 3

When to Transfuse in Dengue

Active Significant Bleeding

• Target platelet count ≥50,000/mm³ for patients with active significant bleeding (gastrointestinal, intracranial, or other major bleeding). 1, 3
• Use 4 units of pooled platelet concentrates or one apheresis unit. 1
• Obtain post-transfusion platelet count to confirm adequate increment. 1

Invasive Procedures

• Major surgery or high-risk procedures: Maintain ≥50,000/mm³ 1, 3
• Lumbar puncture: Transfuse if <50,000/mm³ 1
• Central venous catheter placement: Transfuse if <20,000/mm³ 1

Special High-Risk Situations

Consider transfusion at counts <20,000/mm³ ONLY if multiple risk factors present: 1

• Advanced age 1
• Hypertension 1
• Peptic ulcer disease 1
• Anticoagulant use 1
• Recent trauma or surgery 1

Evidence Against Prophylactic Transfusion

The highest quality randomized controlled trial (372 patients, 2017) demonstrated that prophylactic platelet transfusion in dengue patients with platelets ≤20,000/μL: 2

• Did NOT reduce clinical bleeding (21% transfusion group vs 26% control group, p=0.16) 2
• Caused significantly more adverse events (13 vs 2 events, p=0.0064) including anaphylaxis, transfusion-related acute lung injury, and fluid overload 2

A large retrospective study (788 patients) showed prophylactic transfusion actually: 4

• Delayed platelet recovery to >50,000/mm³ by 1 day (3 days vs 2 days, p<0.0001) 4
• Increased hospital length of stay by 1 day (6 days vs 5 days, p<0.0001) 4
• Did NOT reduce bleeding rates (18.2% vs 23.5%, p=0.08) 4

Post-hoc analysis revealed that patients with poor platelet recovery who received prophylactic transfusion had increased bleeding risk (OR 2.34,95% CI 1.18-4.63). 5

Recommended Management Algorithm

Step 1: Assess for Active Bleeding

• If YES and significant → Transfuse to maintain ≥50,000/mm³ 1, 3
• If NO → Proceed to Step 2

Step 2: Evaluate Need for Invasive Procedures

• Major surgery/high-risk procedure → Maintain 40,000-50,000/mm³ 1
• Lumbar puncture → Transfuse if <50,000/mm³ 1
• Central line → Transfuse if <20,000/mm³ 1
• No procedure planned → Proceed to Step 3

Step 3: Supportive Care Only (Even with Platelets <20,000/mm³)

• Adequate fluid therapy 1
• Fever and pain management (avoid NSAIDs/aspirin) 1
• Serial platelet count monitoring 1
• Bed rest and observation 6

Critical Pitfalls to Avoid

Do NOT transfuse prophylactically based on platelet count alone, regardless of how low the count drops. 1, 2 A restrictive strategy using thresholds as low as 5,000/μL for prophylaxis (with clinical features) proved safe in observational studies. 6

Do NOT use fever alone as an indication for transfusion in dengue, though fever >38°C may be considered alongside other risk factors when determining thresholds. 7

Do NOT assume transfusion will expedite recovery—evidence shows it may delay platelet recovery and prolong hospitalization. 4

Do NOT forget to have additional units available if intraoperative or postoperative bleeding occurs during planned procedures. 1