Platelet volume: laboratory measurement and clinical application.

Modern cell analyzers routinely produce platelet indices, but many clinicians do not utilize them in clinical decision-making. In part this can be attributed to difficulties with their laboratory measurement. The mean platelet volume is dependent on a number of variables, including time of analysis after venepuncture, method of analysis, anticoagulant used and specimen storage temperature. The influence of these laboratory variables is significant and reproducible mean platelet volumes are dependent on standardized laboratory methodology. When pre-analysis factors are controlled, alterations in platelet volume can be demonstrated in a number of disease states and assessment of platelet volume can be useful in the monitoring and diagnosis of patients. An understanding of the pathophysiology of alterations in platelet volume and of the inverse relationship between platelet volume and count is a prerequisite for the successful clinical application of platelet volume measurements.