Role of red cell and platelet indices as a predictive tool for transfusions in dengue

Abstract

Review of literature and prevalent practices show the importance of red cell indices, especially hematocrit(HCT )in the diagnosis and prognosis of dengue. Platelet indices also may act as a tool to assess the prognosis and decide on the need for red cell and platelet transfusions in dengue. Platelet indices such as platelet count, mean platelet volume (MPV), platelet distribution width (PDW), and plateletcrit (PCT) are simple indices which can be done by any 3-part differential cell counter. However, immature platelet fraction (IPF) can be done only at advanced centres using more advanced cell counters. In dengue fever, red cell indices give indirect information on whether the patient is bleeding or going into impending shock. An increased HCT suggests haemoconcentration and warrants treatment with bolus IV fluids while a decreased HCT in an unstable patient may indicate bleeding and act as a predictor for red cell transfusions, whereas it suggests recovery from disease in a stable patient. Platelet counts have no role in determining need for transfusion in dengue. Platelet indices give information on whether the platelet destruction is ongoing (necessitating an impending platelet transfusion) or whether the bone marrow is responsive and platelet transfusions can be put on hold. An increase MPV with falling platelets implies destruction of platelet and signals need for platelet transfusion while a decrease in MPV with low platelets