Normal range values for thromboelastography in healthy adult volunteers

Area of Science:

• Clinical Pathology
• Hematology
• Coagulation Science

Background:

• Thromboelastography (TEG) offers functional coagulation assessment but lacks standardized techniques and normal values, limiting its clinical use, especially in trauma.
• Existing manufacturer-provided normal values may not accurately reflect diverse populations, potentially leading to misdiagnosis.

Purpose of the Study:

• To establish population-specific normal values for TEG parameters using a standardized kaolin-activated method.
• To compare these established values against manufacturer ranges and assess the influence of demographic factors like gender, age, blood type, and ethnicity.
• To evaluate the clinical utility and specificity of manufacturer-derived normal values in a healthy cohort.

Main Methods:

• Standardized TEG analysis was performed on citrated blood from 118 healthy volunteers using a Haemoscope 5000 device with kaolin activation.
• Volunteers were screened for exclusion criteria including pregnancy, anticoagulant use, and bleeding disorders.
• TEG parameters (R, K, alpha, MA, LY30, coagulation index) were analyzed, and individuals outside manufacturer ranges underwent further coagulation investigations.

Main Results:

• Established 95% reference ranges for the study population: R (3.8-9.8 min), K (0.7-3.4 min), alpha (47.8-77.7°), MA (49.7-72.7 mm), LY30 (-2.3-5.77%), and coagulation index (-5.1-3.6).
• Significant differences were observed between established and manufacturer values, with manufacturer ranges potentially misdiagnosing 8.5% of healthy volunteers as coagulopathic (81% specificity).
• Healthy women exhibited significantly higher hypercoagulability compared to men; age and East Asian ethnicity did not correlate with hypo- or hypercoagulability.

Conclusions:

• Institution-specific normal values for TEG are essential for accurate interpretation, as generic ranges may lack specificity.
• The manufacturer's normal values demonstrated suboptimal specificity in this population, underscoring the need for local validation.
• Developing widely accepted, standardized TEG normal values may require multi-institutional collaboration to improve diagnostic accuracy and clinical adoption.