Impact of changes in haematocrit level and platelet count on thromboelastometry parameters

Area of Science:

• Hematology
• Coagulation diagnostics
• Medical device technology

Background:

• Thromboelastometry, particularly with the ROTEM® device, is vital for assessing hemostasis.
• The influence of hematocrit (Hct) and platelet counts (PLT) on these measurements remains incompletely understood.
• Clarifying these dependencies is essential for accurate clinical interpretation.

Purpose of the Study:

• To investigate the extent to which Hct and PLT levels affect key thromboelastometry parameters.
• To determine the quantitative impact of varying Hct and PLT on ROTEM® measurements.
• To provide data for potential adjustments in clinical practice.

Main Methods:

• In vitro preparation of whole blood samples with controlled variations in Hct and PLT.
• Measurement of thromboelastometry parameters including Maximum Clot Firmness (MCF), Clotting Time (CT), Clot Formation Time (CFT), and alpha angle (α).
• Assessment across multiple ROTEM® assays (INTEM, EXTEM, FIBTEM, APTEM).

Main Results:

• Thromboelastometry measurements showed substantial dependence on both Hct and PLT.
• Increasing Hct led to lower MCF and higher CT and CFT.
• Increasing PLT resulted in higher MCF and lower CFT, with no significant effect on CT.

Conclusions:

• Thromboelastometry parameter readings are significantly influenced by Hct and PLT levels.
• Clinical interpretation of ROTEM® results requires adjustment for Hct and PLT to prevent confounding.
• These findings highlight the need for Hct and PLT correction in routine thromboelastometry analysis.