Efficacy of Quantra-Qplus System for Rapid Diagnosis and Treatment of Hypofibrinogenemia and Thrombocytopenia After Cardiopulmonary Bypass.

Objectives: To assess whether the Quantra-Qplus can provide the cutoff values for predicting transfusion thresholds after cardiopulmonary bypass.

Design: Prospective observational study.

Setting: Single-center university hospital.

Participants: Adult patients undergoing cardiac surgery.

Interventions: The Quantra-Qplus and conventional laboratory coagulation test were performed.

Measurements and main results: We enrolled 50 adult patients, and collected blood samples at 4 times (preoperative, during cardiopulmonary bypass, after protamine administration, and at the end of surgery). We obtained the values of the Quantra-Qplus (fibrinogen contribution to clot stiffness [FCS] and platelet contribution to clot stiffness [PCS]) and the values of conventional laboratory coagulation test (fibrinogen concentration and platelet count). To determine the cutoff values for FCS and PCS predicting blood transfusion thresholds at after protamine, receiver operating characteristic curve, area under the curve (AUC) with 95% confidence intervals (95% CIs), and Youden index were used. The cutoff value of FCS for predicting a fibrinogen concentration of less than 150 mg/dL was 0.95 hPa (AUC = 0.94; 95% CI, 0.86-1.00), and PCS for predicting a platelet count of less than 50,000/mm³ was 7.05 hPa (AUC = 0.97; 95% CI, 0.92-1.00) at after protamine administration. The cutoff values of FCS and PC varied during cardiac surgery.

Conclusions: Our study provides potential cutoff values of FCS and PCS to guide fibrinogen administration or platelet transfusion in cardiac surgery patients after protamine administration. These cutoff values might vary during surgery, and different cutoff values for predicting transfusion thresholds during cardiac surgery might apply.