Rotational Thromboelastometry Values After On-Pump Cardiac Surgery – A Retrospective Cohort Study

Abstract

Background Viscoelastic coagulation monitoring is recommended for coagulation management after cardiac surgery, but optimum target values are poorly defined. Aims To determine “to-be-expected” values in rotational thromboelastometry (ROTEM) after heparin reversal, to correlate ROTEM parameters with fibrinogen levels and platelet count, and to estimate the effect of hemoglobin levels on these measurements. Methods We retrospectively analyzed 571 consecutive adult patients undergoing cardiac surgery with cardiopulmonary bypass from 12/2018 to 08/2020. ROTEM and conventional laboratory measurements were performed 5 to 10 minutes after protamine administration. Results Clotting times in EXTEM, INTEM, and FIBTEM were significantly prolonged (72.6%, 96.1%, and 31.8% above reference ranges, respectively). Clot firmness parameters in EXTEM and INTEM were relevantly reduced (7.9% to 14.4% and 9.1% to 32.3% below the reference ranges, respectively). There was an excellent linear correlation of FIBTEM amplitude after 10 min (A10) and of maximal clot firmness (MCF) with fibrinogen concentrations (r = .81 and .80). Areas under receiver operating characteristic (AUROC) for identifying hypofibrinogenemia <1.5 g/L were between .80 and .87. No effect of hematocrit was observed. We also found a linear correlation of EXTEM, INTEM, and EXTEM-FIBTEM at both A10 and MCF with platelet counts (.32 to .68). The AUROCs for identifying thrombocytopenia (<100,000/μL) were .79 to .84, and were greater for A10 than for MCF measurements ( P=.074, .001, and <.001, respectively). Conclusions “To-be-expected” ROTEM values after CPB are different from the published reference ranges. ROTEM parameters might allow for reliable estimation of fibrinogen level and platelet count without being influenced by hematocrit.

Validity and Utility of Early Parameters in TEG6s Platelet Mapping to Assess the Coagulation Status During Cardiovascular Surgery With Cardiopulmonary Bypass

“…MA HKH showed a strong relationship with fibrinogen concentration and platelet count, although K and angle showed moderate relationships with them. These results indicate that the predictive ability of TEG6s Platelet Mapping for conventional coagulation tests is comparable to that of rotational thromboelastometry (ROTEM; TEM Innovations Gmbh, Munich, Germany), which is another popular POC monitoring [ 23 - 25 ]. Furthermore, our study showed that K, angle, and MA HKH could predict the combination of fibrinogen > 150 mg/dL and platelet count > 100,000/µL with clinically acceptable accuracy.…”

Cardiothoracic Anesthesiology: Novel Milestone and Renewed Opportunities

“…Gauger et al hereby study the ROTEM POC testing for accuracy of "to-be-expected" values after cardiac surgery. 18 They demonstrate that ROTEM accurately estimates the fibrinogen level and platelet count. While this is not entirely novel, it does add value as scientific evidence specifically relevant to cardiac surgery and not merely in healthy volunteers.…”