Platelet Transfusion Thresholds: How Low Can We Go in Respect to Platelet Counting?

Abstract

Platelet transfusion is conventionally used to prevent or treat bleeding in patients with low platelet counts or impaired platelet function. The identification of accurate thresholds of platelet count for guiding platelet transfusion practices is a crucial aspect in health care to prevent adverse events, side effects, unwarranted costs for the health care service, and deprivation of supplies. This article is therefore aimed at providing a narrative overview on current guidelines and recommendations for platelet transfusion across many clinical settings, including platelet function disorders, and critically analyzing the available platelet transfusion thresholds according to the current analytical performance of platelet counting with automated hematological analyzers. Overall, universal agreement on the definition of platelet transfusion thresholds has not been reached. The degree of accuracy and imprecision of many fully automated hematological analyzers appears also unsatisfactory, especially at the lower thrombocytopenic range, and this may thus jeopardize the managed care of patients who are candidates for platelet transfusions. Potential solutions to overcome the current shortcomings of automated platelet counting are also discussed, encompassing the use of alternative tests for guiding platelet transfusion (e.g., thrombin generation assays or thromboelastography) along with innovative approaches for platelet enumeration (e.g., fluorescent labeling and flow cytometry).

Multicenter evaluation of analytical performances of platelet counts and platelet parameters: Carryover, precision, and stability

“…These limits must be brought to the attention of the clinician to correctly support a process of clinical decision. 36 Our study further emphasizes that there is a clear requirement to develop suitable internal quality control material to assess performance of HAs for counting severely thrombocytopenic samples and to challenge HAs at the difficult levels of critical clinical decision-making.…”

Bleeding and Bleeding Risk in COVID-19

“…9 These patients are at risk of bleeding, and most guidelines recommend platelet transfusion when their platelet count is between < 30-50 Â 10 9 /L, for bleeders or for those at high risk of bleeding, and < 10 Â 10 9 /L, whether bleeding or not. 10,11 Therapeutic response of platelet replacement is lower in patients with DIC, high fever, or splenomegaly. 10 In the setting of COVID-19, currently lacking randomized clinical trials, there is no definite guidance on threshold for platelet transfusion.…”

Expert consensus on the diagnosis and treatment of thrombocytopenia in adult critical care patients in China

“…However, platelet transfusion is not recommended for patients receiving antiplatelet therapy who have cerebral hemorrhage that does not require surgical treatment [167,168]. The use of platelet count as an indication for platelet transfusions has not been shown to improve the outcomes of critical care patients [169,170]. The use of platelet function parameters to guide platelet transfusion in critical care patients with thrombocytopenia may be beneficial for improving the outcomes of these patients [171][172][173].…”