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Updated: Jun 6, 2026
The Nijmegen Hemostasis Assay: Simultaneous Fluorogenic Measurement of Thrombin and Plasmin Generation in a Single Well
Published on: February 27, 2026
Assessment of thrombin generation measured before and after cardiopulmonary bypass surgery and its association with
1Department of Anaesthetics, Intensive Care and Pain Medicine, School of Medicine, Cardiff University, Heath Park, Cardiff, UK.
Insights
Identifying patients at risk of bleeding after cardiopulmonary bypass (CPB) is crucial. Thrombin generation (TG) testing before and after surgery can predict and identify patients prone to excessive post-CPB bleeding.
Area of Science:
- Cardiovascular Surgery
- Hemostasis and Thrombosis
- Anesthesiology
Background:
- Post-cardiopulmonary bypass (CPB) bleeding is a significant cause of patient morbidity and mortality.
- Effective identification of patients with hemostatic impairment can lead to early intervention and improved outcomes.
Purpose of the Study:
- To investigate whether coagulation screens, factors, thromboelastography (TEG), rotational thromboelastometry (Rotem), and thrombin generation (TG) can identify patients at increased risk of excessive bleeding post-CPB.
- To assess the correlation between pre-operative and post-operative hemostatic markers and bleeding events.
Main Methods:
- Recruited 77 patients undergoing CPB.
- Measured coagulation parameters, factors, TEG, Rotem, and TG pre-surgery and post-heparin reversal.
- Analyzed data to identify predictors of >1000 mL blood loss within 24 hours post-operatively.
Main Results:
- Patients with >1000 mL bleeding had lower platelet counts, factors IX, X, XI, endogenous thrombin potential (ETP), and TG rates, and higher activated partial thromboplastin time (aPTT).
- Post-operative TG and aPTT were significant predictors of bleeding via ROC analysis.
- Reduced pre-operative TG was associated with increased post-operative bleeding.
Conclusions:
- Pre-operative hemostatic defects, particularly in the propagation phase, are worsened by CPB, contributing to post-operative bleeding.
- Pre- and post-operative TG measurements can potentially identify patients at high risk for bleeding after CPB.
Background:
Bleeding after cardiopulmonary bypass (CPB) is a major cause of morbidity and mortality and consumes large amounts of blood. Identifying patients at increased risk of bleeding secondary to hemostatic impairment may improve clinical outcomes by allowing early intervention.
Methods:
This present study recruited 77 patients undergoing CPB and measured coagulation screens, coagulation factors, TEG(®), Rotem(®) and thrombin generation (TG) before surgery and 30 min after heparin reversal. The tests were analyzed to investigate whether they identified patients at increased risk of excess bleeding (defined as > 1000 mL) in the first 24 h postoperatively.
Results:
Patients who bled > 1000 mL had a lower: platelet count (P < 0.02), factors (F)IX, X and XI (P < 0.005), endogenous thrombin potential (ETP) and an initial rate of TG (P < 0.02) and higher activated partial thromboplastin time (aPTT) (P < 0.001) than patients who bled < 1000 mL. Receiver operating characteristic (ROC) analysis was significant for post-operative TG and aPTT (P < 0.001). Furthermore, reduced pre-operative TG was associated with increased postoperative bleeding (P < 0.02). Pre- and postoperative TG were correlated (ρ = 0.7, P < 0.001). TEG(®), Rotem(®) and prothrombin time (PT) at either time point were not associated with increased bleeding.
Conclusion:
These data suggest that pre-operative defects in the propagation phase of hemostasis are exacerbated during CPB, contributing to bleeding post-CPB. TG taken both pre- and postoperatively could potentially be used to identify patients at an increased risk of bleeding post-CPB.
