Platelet size in thrombocytopenia due to sepsis.

In normal persons, the mean platelet volume varies inversely but nonlinearly with the platelet count. Those with immune platelet destruction have a mean platelet volume that conforms to normal values. Nine patients with thrombocytopenia due to post-trauma sepsis without disseminated intravascular coagulation had a lower than normal mean platelet volume as the platelet count fell. In six patients who recovered, the mean platelet volume increased to the normal value before the platelet count began to rise. In contrast, three patients who did not recover from sepsis had no change from the low mean platelet volume and thrombocytopenia. Since mean platelet volume can now be part of the routine blood count, it is a useful variable to assay the degree of bone marrow suppression in the patient with thrombocytopenia and can be used as a predictor of recovery from thrombocytopenia.