Quantra analyzer with the QStat® Cartridge compared with conventional laboratory tests during postpartum hemorrhage:...

Point-of-care viscoelastic testing devices are of interest for rapid detection of obstetric coagulopathy in postpartum hemorrhage (PPH). However, there is a lack of data on the assessment of coagulation during PPH with the new Quantra device based on sonic estimation of elasticity via resonance.

We conducted a retrospective observational cohort study of 130 obstetric patients with PPH with Quantra QStat assessment. Quantra QStat measurements of clotting time (CT), fibrinogen contribution to clot stiffness (FCS) and platelet contribution to clot stiffness (PCS) were compared with the following paired laboratory tests: aPTT, Clauss fibrinogen (CF), and platelet count. The primary aim was to assess correlations between Quantra-QStat measurements and standard laboratory test during PPH. Secondary aims were to investigate the ability of Quantra QStat to diagnose hypofibrinogenemia, thrombocytopenia or coagulation factor deficiencies.

We analyzed 160 paired Quantra QStat and standard laboratory tests. Quantra-QStat tests correlated with laboratory tests as follows: CT with aPTT ratio (r_s = 0.61; P <0.001), PCS with platelet count (r_s = 0.75; P <0.001), and FCS with CF (r_s = 0.84; P <0.001). FCS predicted a CF ≤2 g/L with an AUC of 0.96 (P <0.0001). The optimal cut-off value was 2 hPa. PCS predicted a platelet count < 80,000/μL with an AUC of 0.94 (P <0.0001). The optimal cut-off value was 11.5 hPa, with a sensitivity of 0.89 and a specificity of 0.88. CT predicted an aPTT ratio >1.2 or >1.5 with an AUC of 0.94 (P <0.001) and 0.92 (P <0.0001). The optimal cut-off values were 127 and 133 seconds.

Quantra parameters during PPH provide rapid and reliable detection of blood clotting disorders.