ROTEM Guided Cryoprecipitate Dose: An Audit of Compliance and Efficacy

Abstract

ROTEM Guided Cryoprecipitate Dose: An Audit of Compliance and Efficacy Anthony Yap1, Oscar Boag Taylor1,2, Hawn Trinh1,2, Coralie Williams3,4, Keith Kelly2, Catherine Downs1,2 1 UNSW School of Clinical Medicine, Sydney NSW, Australia. 2 Prince of Wales Department of Anaesthesia, SESLHD, Sydney NSW. 3 Ecology and Evolution Research Centre, UNSW, Sydney, Australia. 4 School of Mathematics and Statistics, UNSW, Sydney, Australia

Background Rotational thromboelastometry (ROTEM) is a rapid viscoelastic haemostatic assay that assesses patient coagulation and guides targeted transfusion with an evidence-based algorithm1. The FIBTEM A5 parameter of a ROTEM test correlates with a patient’s blood fibrinogen level, correction of which can help to control a critical bleed2,3. To achieve this, the Randwick ROTEM algorithm’s FIBTEM step advises tiered cryoprecipitate dosing. Clinician compliance is essential to utilise the potential benefits of a ROTEM-guided transfusion, however, there is a relative lack of literature in this area. Existing ROTEM efficacy studies often do not account for compliance, obscuring the true benefits of ROTEM-guided care. This study aimed to: 1. Audit clinician compliance with the FIBTEM step of the Randwick ROTEM algorithm. 2. Assess the efficacy of the Randwick FIBTEM step at increasing FIBTEM A5 through tiered apheresis cryoprecipitate dosing recommendations.

Methods This was a retrospective cross-sectional study of ROTEM tests conducted at the cardiothoracic surgical unit and cardiothoracic intensive care unit from 01 January 2024 to 13 February 2025. This Randwick ROTEM algorithm recommends a weight-adjusted apheresis cryoprecipitate dose when a critically bleeding patient’s FIBTEM A5 drops below 12mm (Figure 1).

COMPLIANCE: 276 ROTEM tests met the following inclusion criteria: measured FIBTEM A5 level below 12mm, recorded patient weight (kg) and had a cryoprecipitate transfusion to the patient within 4 hours. There were 42 voluntary REDCap surveys where clinicians reported whether they believed their transfusion was algorithm-compliant. 3 dose ratio transfusion categories were defined by dividing the units of cryoprecipitatetransfused by units recommended by the algorithm. • Excessive Transfusion: >1.25 (non-compliant) • Compliant Transfusion: 0.75 - 1.25. • Insufficient Transfusion: <0.75 (non-compliant) EFFICACY: Of the 276 ROTEM tests, 108 were linked to a subsequent ROTEM test within 12 hours. Only the first pairs were analysed. A cryoprecipitate transfusion response was defined as “corrected” if the subsequent FIBTEM A5 normalised to 12mm or greater. It was defined as “non-corrected” if the FIBTEM A5 remained below 12mm.

Results: Compliance Figure 2 displays the percentage proportion of transfusions that were excessively, insufficiently or compliantly dosed at various FIBTEM A5 ranges. The majority, 177/294 (60.2%), of ROTEM tests received a compliant transfusion response at the 2 locations audited. There was a strong concordance between a clinician’s belief of their compliance (subjective) with compliance as defined by the dose ratio (objective). (Figure 3)

Results: Efficacy Figure 4 displays whether subsequent FIBTEM A5 measurements corrected in response to transfusion responses at the three dose ratios. Compliant transfusions led to FIBTEM A5 correction in the majority, 65.2% (45/69), of the subsequent test. No corrected FIBTEM A5 exceeded 25mm. Excessive Transfusions • FIBTEM A5 correction occurred in 92.3% (24/26) of the subsequent test. • Relative to a compliant transfusion response, the odds of FIBTEM A5 normalisation increased by 6.30 times (95% CI, 0.53 – 33.90, p = 0.013). Insufficient Transfusions • FIBTEM A5 correction occurred in only 38.5% (5/13) of the subsequent test. • Relative to a compliant transfusion response, the odds of FIBTEM A5 normalisation decreased by 0.71 times (95% CI, 0.05 – 0.92, p = 0.06).

Conclusions Compliance: Randwick campus clinicians at the CTICU and CTSU were mostly compliant with their transfusions. Other studies reported lower compliance rates where the endpoint for compliance was only the correct blood product given, without consideration of the dose4. Efficacy: This study found that the FIBTEM step was effective. Compliant transfusions, using the tiered algorithm, corrected most FIBTEM A5 in a single dose intervention. Relative safety was observed as no FIBTEM A5 corrected beyond 25mm, even with excessive dosing. Future Directions: This study was limited by the small sample sizes in ROTEM tests with lower FIBTEM A5, as well as REDCap responses. To address this, the REDCap survey should be simplified and a continuing audit of the new Randwick algorithm should be conducted. Future studies should also review complications related to ROTEM usage and analyse efficacy through investigation of bleeding cessation as a clinical endpoint. The trends underpinning excessive and insufficient transfusions should be identified and targeted to improve transfusion practice. Figure 4 displays whether subsequent FIBTEM A5 measurements corrected in response to transfusion responses at the three dose ratios. Compliant transfusions led to FIBTEM A5 correction in the majority, 65.2% (45/69), of the subsequent test. No corrected FIBTEM A5 exceeded 25mm. Excessive Transfusions • FIBTEM A5 correction occurred in 92.3% (24/26) of the subsequent test. • Relative to a compliant transfusion response, the odds of FIBTEM A5 normalisation increased by 6.30 times (95% CI, 0.53 – 33.90, p = 0.013). Insufficient Transfusions • FIBTEM A5 correction occurred in only 38.5% (5/13) of the subsequent test. • Relative to a compliant transfusion response, the odds of FIBTEM A5 normalisation decreased by 0.71 times (95% CI, 0.05 – 0.92, p = 0.06).

References 1. Drotarova M, Zolkova J, Belakova KM, et al. Basic Principles of Rotational Thromboelastometry (ROTEM®) and the Role of ROTEM-Guided Fibrinogen Replacement Therapy in the Management of Coagulopathies.Diagnostics (Basel). 2023;13(20):3219. Published 2023 Oct 16. doi:10.3390/diagnostics13203219 2. de Vries JJ, Veen CSB, Snoek CJM, Kruip MJHA, de Maat MPM. FIBTEM clot firmness parameters correlate well with the fibrinogen concentration measured by the Clauss assay in patients and healthy subjects.Scand J Clin Lab Invest. 2020;80(7):600-605. doi:10.1080/00365513.2020.1818283 3. Blayney A, McCullough J, Wake E, et al. Substitution of ROTEM FIBTEM A5 for A10 in trauma: an observational study building a case for more rapid analysis of coagulopathy.Eur J Trauma Emerg Surg. 2022;48(2):1077-1084. doi:10.1007/s00068-021-01652-w 4. Harish V, Postill G, Al-Haimus F, et al. Adherence to local rotational thromboelastometry recommendations in the care of trauma patients: A retrospective cohort study.Transfusion. 2025;65(9):1716-1727. doi:10.1111/trf.18349 Figure 2: Histogram Showing the Percentage Proportions of Three Dose Ratio Transfusion Categories at Various FIBTEM Ranges Figure 3: Pie Graphs Comparing Subjective and Objective Compliance Figure 4: Sankey Diagram Displaying FIBTEM A5 Correction Rates at the Three Dose Ratio Transfusion Categories