Platelet Transfusion in Dengue Patients
Dr Chhavi Gupta M.B.B.S, DCP (Pathology), PGDHA
Dr Anshu Gupta M.B.B.S, MD (Pathology)
Introduction
As we all know, Dengue fever is a major public health problem in India. Delhi is one of the big cities in India where dengue is endemic during monsoon season .The demand for platelets in the two forms Single Donor Platelet Concentrate (SDPC) and Random Donor
Platelet Concentrate (RDPC) increases during this time. Platelet transfusions are used to prevent spontaneous bleeding or to stop established bleeding in patients with a deficiency in platelet number or function. Platelet transfusion is indicated prophylactically for patients who have platelet count less then or equal to 20000/ul to prevent bleeding. In Dengue patients, transfusion is done when platelet count is 10000-20000/ul and thrombocytopenic bleeding is present. All the patients of Dengue Shock syndrome require platelet support .
Dengue patients can be categorized into the four categories based on their platelet count:
1. High risk
2. Moderate risk
3. Low risk
4. No risk
High risk patient
The patients belonging to this group have platelet count <20,000/cumm and they are at high risk of bleeding. Such patients should be receiving prophylactic platelet transfusion. The patients in this category whose platelet count is less than 10,000/cumm have even a greater risk and need to be prioritized.
Moderate risk
All the patients whose platelet count is in between 21-40,000/cumm belong to moderate risk category. The patients of this risk group should be transfused with platelet only if they have any hemorrhagic symptoms.

Low risk
Those patients whose platelet count >40,000/cumm but <100,000/cumm for the age and sex should be observed and monitored carefully but should not receive unnecessary platelet transfusion because of the risk of transmission of blood borne infection (with no benefit of platelet transfusion).
No risk category
Patients falling in this category usually have the platelet count >100,000/cumm. They should never be transfused with platelet and should be managed on intravenous fluids and supportive therapy.
The two forms of Platelet Concentrate are :
Random Donor Platelet Concentrate (RDPC) is prepared from 450ml whole blood and separation of platelets is done within 6-8 hours after phlebotomy. A unit of platelet concentrate prepared by this method contains at least 5.5X10
10 platelets. With the help of this method, the platelet count is elevated to 5000-10000/ul in an adult of approximately 70kg body weight and a single unit is adequate for transfusion to neonates or infants but for adults,
6-10 units are required for one therapeutic dose. So the recipient is exposed to a large number of allogenic donors.
Single Donor Platelet Concentrate (SDPC) is prepared by the plateletpheresis procedure in which a portion of the donor’s platelet and some plasma is removed and the Red Blood
Cells, White Blood Cells and remaining plasma are returned back to the donor. Also, the platelet component should be group specific or plasma compatible and should not contain clinically significant red cell antibodies. A unit of platelet concentrate prepared by this method contains 3-7X10 11 platelets and the platelet count is elevated to 30000-70000/ul in an adult of 70kg weight. Single unit of platelets prepared by apheresis procedure have a platelet content similar to that of 6-8 units of pooled platelets or RDPCs. In SDPC transfusion, recipient gets exposed to one donor per transfusion.

In the end we want to conclude the following:
All hospitalized dengue patients can be categorized into the high, moderate, low and no risk patients based on their platelet count at the time of hospitalization. The high-risk patients should be given priority and the treating physician should take decision for platelet transfusion. Moderate risk patients should be observed carefully and platelet is transfused only if they have any hemorrhagic manifestations. Low risk patients should not be given platelet transfusion and should be managed on intravenous fluids and supportive therapy
RDPC
1. Contains 5.5X10
10 platelets.
2. Plasma Volume is 50-60 ml.
3. WBC Count is 10 8 in each unit.
4. RBC Count is more.
5. Increases Platelets Count from 5000-
10000/ul.
6. Exposes recipient to large number of donors.
7. More exposure to infections.
8. More risk of bacterial contamination.
SDPC
1. Contains 3-7X10 11 platelets.
2. Plasma Volume is 200 ml.
3. WBC Count is less than 5.5X10
6 in each unit.
4. RBCs are in traces.
5. Increases Platelet Count from 30000-
70000/ul.
6. Exposes recipient to only one donor per transfusion.
7. Less exposure to infections.
8. Decreases risk of bacterial contamination and easy handling.

References
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Authors:
Dr Chhavi Gupta M.B.B.S, DCP (Pathology), PGDHA, Senior Resident, Emergency Lab, IHBAS,
Dilshad Garden, Delhi, Mobile: 9899207036, e mail id: Drchhavi_gupta@yahoo.com
Dr Anshu Gupta M.B.B.S, MD (Pathology) ,Associate Professor, Department of Pathology, IHBAS,
Dilshad Garden, Delhi , Mobile 9868396812, e mail id: dransh2002@yahoo.co.in