What is the role of platelet (platelets) concentrate in managing dengue patients with severe thrombocytopenia (low platelet count)?

Role of Platelet Concentrate in Dengue

Prophylactic platelet transfusion should NOT be routinely administered to dengue patients with thrombocytopenia, as it does not prevent bleeding and may increase adverse events including potentially worsening bleeding risk. 1

Evidence Against Routine Prophylactic Transfusion

The highest quality evidence comes from a multicenter randomized controlled trial specifically examining dengue patients with severe thrombocytopenia (≤20,000/μL). This landmark study demonstrated:

• No reduction in clinical bleeding when prophylactic platelet transfusion was added to supportive care compared to supportive care alone (21% vs 26% bleeding rates; p=0.16) 1
• Significantly increased adverse events in the transfusion group (13 events vs 2 events; p=0.0064), including serious complications such as anaphylaxis, transfusion-related acute lung injury, and fluid overload 1
• Paradoxically increased bleeding risk in patients with poor platelet recovery who received transfusions (odds ratio 2.34) 2

When Platelet Transfusion May Be Indicated

Therapeutic (not prophylactic) platelet transfusion should be reserved for:

• Active severe bleeding (hematemesis, melena, menorrhagia, intracranial hemorrhage) requiring hemostasis 3, 4
• Planned invasive procedures or emergency surgery requiring platelet counts >50,000/μL 3
• Platelet counts <5,000/μL in select high-risk patients 3
• Platelet counts <20,000/μL with concurrent bleeding manifestations (petechiae, gum bleeding, epistaxis) AND additional risk factors 3, 4

Recommended Management Algorithm

For platelet counts ≤20,000/μL without bleeding:

• Provide supportive care only (bed rest, fluid therapy, fever/pain management) 1
• Monitor closely for bleeding signs 3
• Avoid prophylactic transfusion 1

For platelet counts ≤20,000/μL with active bleeding:

• Administer 4-8 platelet concentrates or one apheresis pack 5
• Target platelet count >50,000/μL for hemostasis 3

For planned invasive procedures:

• Transfuse to achieve platelet count >50,000/μL 3

Critical Pitfalls to Avoid

Do not transfuse based solely on platelet count. The 2017 randomized trial definitively showed that 84.88% of dengue patients develop thrombocytopenia, but only 9.7% experience actual bleeding 4. Transfusing all thrombocytopenic patients leads to unnecessary exposure to transfusion risks 1.

Recognize that platelet transfusion may worsen outcomes in certain patients. Those with poor platelet recovery (remaining ≤20,000/μL on day 2) who receive transfusions have MORE than double the bleeding risk compared to those managed conservatively 2. The mechanisms remain unclear but may relate to immune-mediated platelet destruction or endothelial dysfunction specific to dengue pathophysiology 2.

Predictors of poor platelet recovery include:

• Older age 2
• Earlier presentation in illness course 2
• Lower white blood cell counts 2

Dosing When Transfusion Is Indicated

When therapeutic transfusion is necessary, administer 4-8 platelet concentrates (pooled) or one apheresis pack 5. Each pooled unit should increase platelet count by 5-10 × 10⁹/L in a 70-kg recipient 5.

Alternative Approaches

A restrictive transfusion strategy based on clinical features rather than arbitrary platelet thresholds has proven feasible and safe, with one observational study showing only 9 of 350 dengue patients (2.6%) required transfusion using strict clinical criteria 3. This approach dramatically reduces unnecessary transfusions while maintaining patient safety 3.