Comparison of Coagulation Parameters in Arterial and Venous Blood in Cardiac Surgery Measured Using the Quantra System

Abstract

Objective: Perioperative coagulation testing often is performed with arterial samples even though device reference ranges typically are established in venous samples. Although limited studies exist comparing coagulation parameters across sampling sites, viscoelastic testing devices have demonstrated some differences. The objective of this study was to compare coagulation parameters determined using the Quantra System for venous and arterial samples. Design: Prospective, observational study. Setting: Tertiary care university hospital. Participants: The study comprised 30 adult patients undergoing cardiac surgery. Interventions: Paired arterial and venous samples were obtained at 2 of the following time points: baseline, during bypass, or after protamine reversal of heparin. Quantra measurements included Clot Time (CT), Heparinase Clot Time (CTH), Clot Time Ratio (CTR), Clot Stiffness (CS), and Fibrinogen (FCS) and Platelet (PCS) Contributions to clot stiffness. Measurements and Main Results: The relationship and agreement between matched data pairs were established and statistical analysis was performed via paired t tests. CTR, CS, FCS, and PCS were unaffected by the sampling site, whereas CT and CTH demonstrated statistically significant differences between arterial and venous samples (p < 0.001). Arterial clot times were prolonged relative to the venous ones with a mean percent error of 14.2 % and 11.9 %, respectively. These results are in general agreement with those reported for other viscoelastic testing devices. Conclusions: This study demonstrates that Quantra clot stiffness-based parameters (CS, FCS, PCS) are unaffected by sampling site, whereas the clot time parameters (CT and CTH) show good correlation in the presence of a bias. CTR, a ratio of CT and CTH, also is unaffected.

Clinical utility of the Quantra® point‐of‐care haemostasis analyser during urgent cardiac surgery

“…We only tested blood taken from the arterial cannula, as recommended by Groves et al. . Compared with before bypass, a significant decline in platelet count and fibrinogen was observed after bypass (after protamine).…”

“…We studied patients undergoing urgent surgery for unstable cardiac disease, who were nearly all taking antiplatelet medication; 68% of patients were transfused Viscoelastic testing devices can be used before, during and after bypass to assess the coagulation system, but not all parameters during the three time-points are equally valid at predicting bleeding and guiding the use of blood products [2,7,9]. We only tested blood taken from the arterial cannula, as recommended by Groves et al [18]. Compared with before bypass, a significant Our study was not designed to change transfusion management, but rather to test the utility and feasibility of the Quantra System before, during and after bypass.…”

Prediction of hypofibrinogenemia and thrombocytopenia at the point of care with the Quantra® QPlus® System

“…Output parameters include a series of clot times and clot stiffness values that represent the functional role of the major components of coagulation, including fibrinogen and platelets. The QPlus Cartridge parameter Fibrinogen Contribution to clot stiffness (FCS) has been previously shown to correlate with laboratory-based fibrinogen assays, whereas the Platelet Contribution to clot stiffness (PCS) parameter has been shown to integrate information about platelet number and platelet function [18][19][20][21][22][23]. A detailed description of the Quantra analyzer and the QPlus Cartridge parameters is presented elsewhere [18,19].…”

“…The QPlus Cartridge parameter Fibrinogen Contribution to clot stiffness (FCS) has been previously shown to correlate with laboratory-based fibrinogen assays, whereas the Platelet Contribution to clot stiffness (PCS) parameter has been shown to integrate information about platelet number and platelet function [18][19][20][21][22][23]. A detailed description of the Quantra analyzer and the QPlus Cartridge parameters is presented elsewhere [18,19]. The performance of the Quantra QPlus System has been established in a series of clinical studies in cardiac and spine reconstruction surgery [18][19][20][21][22][23][24][25].…”

Assessment of platelet function utilizing viscoelastic testing

“…58 Additionally, observational studies are attempting to lay groundwork for Quantraʼs potential clinical use by first assessing PLT contribution to clot stiffness in patients undergoing cardiac surgery and with some studies comparing its values to those of other VET. 58,60,[67][68][69][70] Only small in vitro studies have assessed Sonoclotʼs ability to monitor PLT function and detect therapeutic GPIIb/IIIa inhibition. One such study had found PF to be comparable to turbidimetric PLT aggregometry in its ability to detect pharmacological GPIIb/IIIa inhibition by tirofiban.…”