Authors: Noteboom S H et al.
Anesthesia & Analgesia 141(3), September 2025
This multicenter expert-panel study examined how consistently experienced clinicians interpret rotational thromboelastometry (ROTEM) results in cardiac surgery patients and how those interpretations compare with a standardized ROTEM-guided algorithm. Given the widespread use of viscoelastic assays to guide transfusion decisions, understanding the reliability and limitations of interpretation is critical.
The investigators analyzed 343 ROTEM measurements from 90 cardiac surgery patients at four perioperative time points: before induction, after aortic declamping, following coagulation correction, and early ICU admission. An international panel of seven cardiovascular anesthesiologists and one intensivist independently reviewed the ROTEM data, identifying coagulopathies and recommending interventions. Interrater reliability was assessed using Fleiss’ kappa for binary decisions and simple matching coefficients for categorical judgments, while intrarater agreement between expert judgment and a ROTEM-based algorithm was also evaluated.
Overall, expert agreement was high. Interrater reliability for binary clinical decisions was substantial to almost perfect at most time points, although agreement dropped after aortic declamping, likely reflecting the complex and rapidly changing coagulation environment at that stage. Agreement on the type of coagulopathy and recommended intervention was good to excellent across all measurement periods. Intrarater agreement was also strong, indicating internal consistency in expert decision-making.
However, meaningful differences emerged when expert recommendations were compared with the ROTEM-guided algorithm. Experts more frequently recommended fibrinogen concentrate and protamine, whereas the algorithm favored plasma and prothrombin complex concentrate. These discrepancies highlight the importance of clinical context, including surgical stage, patient-specific factors, and nuanced pattern recognition that may not be fully captured by fixed algorithmic cutoffs.
The authors conclude that while trained experts interpret ROTEM data with high consistency, reliance on rigid algorithms alone may oversimplify complex coagulation states in cardiac surgery. Future decision-support tools should move beyond predefined thresholds and incorporate individualized, data-driven approaches to better align with expert clinical reasoning and improve patient outcomes.
Key Points
Expert interpretation of ROTEM in cardiac surgery shows high inter- and intrarater reliability.
Agreement is strongest for identifying abnormalities and guiding treatment, but varies by surgical phase.
Algorithms and experts often diverge in transfusion recommendations, particularly for fibrinogen, plasma, PCC, and protamine use.
Clinical context remains essential when interpreting viscoelastic assays.
More personalized, adaptive decision-support systems are needed to complement ROTEM use in practice.
This article has not been done before and is not a duplicate of any prior summaries in our catalog.
Thank you to Anesthesia & Analgesia for allowing us to summarize and discuss this article.