Reduce transfusions with Quantra-guided algorithm for high-risk bleeding
Cardiac studies confirm performance, speed and accuracy
Recent cardiac studies into the management of high-risk bleeding show the effectiveness of the Quantra Haemostasis Analyser and its QPlus cartridge. This novel, point-of-care solution enhances viscoelastic (VET) testing using ultrasound technology.
Zlotnik et. al. reported on a ‘before and after’ study which compared, for the first time, a Quantra-guided haemostatic algorithm with one based on standard laboratory testing. Quantra outperformed the lab, significantly reducing transfusion of RBCs, FFP and platelets. A reduction in major bleeding was also noted (36% v 56%, p = 0.014 in the Quantra group). Zlotnik also refers to numerous clinical guidelines that now recommend VET as part of a goal-directed treatment algorithm for dealing with coagulopathic bleeding. [1]
Active role in PBM protocols
A second study by Tibi et. al focused on the need for blood products before and after the integration of a Quantra – guided algorithm into their patient blood management (PBM) protocols. [2]
Across all types of blood products, the total number of units given in the post-Quantra cohort was less than in the pre-Quantra cohort. However, the decrease in FFP was especially marked, with 34 units in the pre-Quantra cohort and only one unit, post-Quantra. The study also highlighted the speed of the Quantra compared to standard laboratory tests. Decisions on whether to transfuse could be made more quickly – and with greater confidence. Both studies reported that using Quantra as part of an active bleeding management protocol for cardiac surgery patients led to a reduction in transfusions.
Tibi also observed that “operated at the point of care with no sample manipulations required, results were available in less than 15 mins, which allowed us to rapidly restore haemostatic balance in these patients”. The study further pointed out how the system quantifies and trends (taking serial measurements) the function of the enzymatic clotting factors, as well as the relative function of platelets and fibrinogen. This enabled “a streamlined goal-directed treatment algorithm”.
Unique PCS parameter
Quantra uses whole blood to identify coagulopathic bleeding. It is the only VET system able to directly deliver platelet contribution to clot stiffness with its platelet contribution to clot stiffness (PCS) parameter. This is calculated on the difference between the overall clot stiffness and the fibrinogen contribution to clot stiffness.
The Quantra was compared with another VET system in a third study. Here, the impact of the PCS parameter was noted, showing how well it correlated with platelet count and function, and that “the best performance in terms of major bleeding prediction (relating to platelets) was obtained by the Quantra PCS’, with AUC = 0.80 (95% CI, 0.600-0.91). [3]
While platelet count is a known predictor of major bleeding, its turn-around time is far longer that the Quantra PCS. Baryshnikova et. al. point to the parameter’s superior level of discrimination with a value available “in a few minutes, enabling faster intervention to prevent/ stop bleeding”. Baryshnikova also notes the importance of having a test that incorporates platelet count and function, “because under the conditions of thrombocytopenia and/or platelet dysfunction, in a bleeding patient, the therapeutic approach remains the same”.
Reverse heparin with confidence
Finally, just published in Perfusion, the first study to assess the correlation of another Quantra parameter, the clot time ratio parameter (CTR) with anti-Xa in ex-vivo heparinised samples. [4] This was initiated because an unusual number of patients with haemostatic abnormalities had been noted in the immediate postoperative period. The reason was found to be incomplete heparin reversal due to insufficient protamine being delivered. The study assessed the ability of POC coagulation tests to detect residual heparin so that protamine can be given more efficiently, rather than unnecessary allogenic blood products. The Quantra was found to ‘reliably detect residual heparin during cardiac surgery’.
Effective, cost-saving tool
These studies confirm Quantra as a cost-saving tool for managing high risk bleeding during surgery, providing rapid results – within 15 minutes – that strongly correlate to standard lab tests. Clinicians working with Quantra have confidence that this novel VET system conserves the use of allogenic blood products while improving patient outcomes. Further, it supports the use of PBM protocols so that goal-directed treatment can be fully implemented.
References
1. Zlotnik D, Georges A, Lang E, et. al. Assessment of a Quantra- Guided Hemostatic Algorithm in High-Bleeding-Risk Cardiac Surgery. Journal of Cardiothoracic and Vascular Anesthesia 000 (2023) 1 – 8. doi: https://doi.org/10.1053/j.jvca.2023.01.034
2. Tibi, P., Thompson, J., Attaran, S. et. al. Retrospective study assessing outcomes in cardiac surgery after implementation of Quantra. Journal of Cardiothoracic Surgery 18, 149 (2023). doi: https://doi.org/10.1186/s13019-023-02245-x
3. Baryshnikova E, Di Dedda U, Ranucci M. Are viscoelastic tests clinically useful to identify platelet-dependent bleeding in high risk cardiac surgery patients? Anesthesia & Analgesia. 022;135:1198-1206. doi: https://doi.org/10.1213/ANE.0000000000006231
4. Tiquet B, Pihan F, Thomasset P, et. al. Clues of incomplete reversal of heparin in cardiac surgery. Perfusion. Feb 22, 2023. [Online ahead
of print]. doi: https://doi.org/10.1177/02676591231160268
