The Bleeding Time as a Screening Test for Evaluation of Platelet Function

TLDR

Normal platelet counts yield a bleeding time of about 4.5 minutes, while lower counts produce a linear increase to roughly 30.5 minutes at 10,000 /µL. The study evaluated a standardized bleeding time template in 100 healthy volunteers and 136 patients with diverse disorders. Prolonged bleeding times indicate platelet dysfunction from aspirin, uremia, or von Willebrand disease, whereas shortened times signal enhanced platelet activity seen in ITP or post‑chemotherapy recovery, demonstrating the test’s utility for systematic platelet function screening.

Abstract

The value of the standardized template bleeding time was studied in 100 normal subjects and 136 patients with various disorders. With normal platelets the bleeding time in this test is 4.5 ± 1.5 minutes (± 1 S.D.) when the circulating platelet concentration exceeds 100,000 per microliter, and is 30.5 – (platelet count per μl/3850) minutes at platelet counts between 100,000 and 10,000 per microliter. More prolonged bleeding times reflect impaired platelet function, as associated with acetylsalicylic acid ingestion, uremia, or von Willebrand's disease. In contrast, bleeding times shorter than predicted with normal platelets are due to increased hemostatic competence of young platelets, associated either with idiopathic thrombocytopenic purpura or with bone-marrow recovery after chemotherapy. The standardized bleeding time measures the overall hemostatic role of platelets in vivo, and is thus suitable for systematic screening.