Prediction of Hypofibrinogenemia and Thrombocytopenia at the Point of Care with the Quantra® QPlus® System

INTRODUCTION:Low fibrinogen and platelet counts are associated with bleeding and the need for transfusion. In this study, we investigated whether the Quantra® QPlus® parameters Fibrinogen Contribution (FCS) and Platelet Contribution (PCS) to clot stiffness could predict commonly used fibrinogen and platelet transfusion thresholds in patients undergoing major surgical procedures. METHODS:This study used data from a multicenter, prospective observational study of adult patients undergoing cardiac or major orthopedic surgery. Quantra and laboratory assays were performed in parallel at multiple time points. Logistic regression models were used to assess the ability of FCS and PCS to predict fibrinogen and platelet thresholds used to guide transfusions. Receiver operating characteristics (ROC) curves were analyzed to determine the diagnostic accuracy and the optimal FCS and PCS values corresponding to the laboratory-based thresholds. RESULTS:The areas under the ROC curves (AUCs) for FCS at fibrinogen thresholds of <120, 150, and 200 mg/dl ranged from 0.96 to 0.89. Similarly, for PCS at platelet thresholds of <50, 80, 100,000/μl, AUCs ranged from 0.95 to 0.89. The proposed optimal FCS and PCS cutoff values showed high negative predictive value and high sensitivity and specificity (both >86%) at the lowest fibrinogen and platelet threshold levels. CONCLUSIONS:This study identifies potential cutoff values for QPlus FCS and PCS proposed for use in place of or in conjunction with laboratory-based assays fibrinogen and platelet thresholds to guide transfusion decisions in surgical patients. These cut-off values will need to be validated in future studies.