Postoperative bleeding remains a significant complication in on-pump cardiac and vascular surgeries. This study, conducted at the Heart Center Dresden, TUD Dresden University of Technology, examines whether on-pump FIBTEM-A5 measurements assessing fibrinogen-dependent clot firmness can accurately predict values after protamine administration. Given that heparin and CPB significantly alter coagulation dynamics, precise monitoring of fibrinogen levels is crucial for optimizing blood management strategies.
Study Design and Methodology
This single-center retrospective observational study included patients undergoing on-pump cardiac surgeries between May 2022 and February 2024. The key inclusion criterion was the availability of intraoperative ROTEM (rotational thromboelastometry) examinations during CPB, with follow-up testing immediately after protamine infusion. Patients receiving fibrinogen concentrate or fresh frozen plasma between tests were excluded to avoid confounding factors.
FIBTEM-A5 values clot firmness at five minutes were analyzed using the Wilcoxon signed rank test for non-normally distributed data. Linear regression analysis determined the relationship between on-pump and post-protamine FIBTEM-A5 values.
Key Findings
The study included 70 patients after screening 143 for eligibility. A statistically significant but minor difference was observed between FIBTEM-A5 values during CPB (median: 16.0mm) and post-protamine administration (median: 15.5mm, p = 0.021). However, regression analysis demonstrated a strong predictive relationship (R = 0.902, R² = 0.813), suggesting that on-pump FIBTEM-A5 measurements can reliably forecast post-protamine levels.
Clinical Implications
These findings have important implications for perioperative coagulation management in cardiac surgery. Since ROTEM provides point-of-care coagulation assessment, integrating on-pump FIBTEM-A5 into transfusion protocols could optimize fibrinogen supplementation, reducing excessive bleeding and unnecessary blood product use. Early identification of fibrinogen deficiency could enhance patient outcomes by minimizing bleeding complications and transfusion-related risks.
Study Limitations
The retrospective design introduces potential selection biases, as only patients requiring repeat ROTEM testing post-protamine were included. Additionally, while strong correlations were observed within normal fibrinogen ranges, extrapolation to low FIBTEM-A5 values remains uncertain. Future research should investigate whether early intervention based on on-pump ROTEM values improves clinical outcomes.
Conclusion
This study demonstrates a strong correlation between on-pump FIBTEM-A5 and post-protamine values, suggesting its utility in guiding fibrinogen supplementation strategies. Future prospective trials are needed to establish definitive clinical guidelines and assess the impact on postoperative bleeding management.
Study Ranking:
5 (Highest Quality) – This study is well-conducted, featuring robust statistical analysis, a clear hypothesis, and strong clinical implications.
