Evaluation of between-, within- and day-to-day variation of coagulation measured by rotational thrombelastometry (ROTEM). (17th November 2017)

• Record Type: Journal Article
• Authors: Jilma-Stohlawetz, Petra; Fritsche-Polanz, Susanne; Quehenberger, Peter; Schörgenhofer, Christian; Bartko, Johann; Ristl, Robin; Jilma, Bernd
• Is Part Of: Scandinavian journal of clinical & laboratory investigation. Volume 77:Number 8(2017)
• Page Start: 651
• Page End: 657
• Publication Date: 2017-11-17
• Subjects: Point of care testing -- biological variation -- reproducibility -- rotational thromboelastometry -- body mass index -- human; Clinical biochemistry -- Periodicals; Physiology, Pathological -- Periodicals; Physiology, Experimental -- Periodicals; Medicine -- Research -- Periodicals; Clinical medicine -- Periodicals; 616.0072
• DOI: 10.1080/00365513.2017.1394487
• Languages: English
• ISSNs: 0036-5513

Abstract

Abstract: Background and aims: The aim of this study was to assess the circadian variation and the between- and within-subject variation in 10 healthy subjects over a period of 8 weeks by ROTEM ® . We further evaluated the influence of elevated body mass index and the effect of low molecular weight heparin and antithrombin on clot formation. Methods: Citrated blood samples were analysed in the NATEM ® test system. The clotting time (CT), clot formation time (CFT), maximum clot firmness (MCF) and the maximum lysis (ML) were assessed. Results: Duplicate measurements showed that 23% of the CT and 31% of the CFT measurements had a coefficient of variation (CV) greater than 10%. The within-subject CV was 16% for the CT and 30% for the CFT. The MCF was fairly constant (6%), whereas ML showed more variation (18%). The between-subject CV was 6% for the CT and 20% for the CFT. Analytical variability was improved by summing up CT and CFT. Compared to morning values, CT, CFT and the sum of CT + CFT were shortened in the afternoon. High body mass index was associated with faster clotting. High concentrations of antithrombin had similar effects on clot formation as 0.2 IU/ml of enoxaparin. Conclusions: To overcome the influence of diurnal variation, we recommend obtaining blood samples at specified times in the morning. The within-subject variation should be taken into account, when serial measurements of drug effects are required.