Background and Goal of Study: 
Extem withdrew Fibtem calculated by rotation thromboelastmetry (ROTEM) was reported to be reflect for platelet count1).  But Solomon et. al.2) reported that Extem -Fibtem did not refer to the accurate platelet counts and function. They suggested new parameter, clotting elasticity (CE) calculated by ROTEM value, which could reflect the accurate platelet count and aggregation. The aim of study is to investigate which measurements are more accurate for platelet counts and seek the normal range of CE as well. 
Materials and methods:	
Patients scheduled cardiac surgery with cardiopulmonary bypass (CPB) were assessed for eligibility. The criteria of transfusion were indicated below, such as hemoglobin >9~10mg/dl, fibrinogen > 150~200mg/dl, platelet count > 50,000~100,000/μl. The heparin dose during CPB was administered 300~400U/kg to target activated clotting time (ACT)>450sec and reversed by protamine sulfate 60~100% dose of heparin. The hemostatic therapy was such as concentrated red cells (CRCs; 140g/unit), fresh frozen plasma (FFP; 120g/unit), and platelet concentration (PC; i.e.,10unit originated from two liter of blood). We collected the samples in four points, after anesthesia introduction (baseline), just after CPB starting, weaning time from CPB, and the end of surgery. 
Results and Discussion: 
Seventy patients were enrolled in the study and we collected 280 points of blood samples to compare the relation between platelet counts and Extem-Fibtem A10 or CE. We also presented the correlation graph between them at figure A and B below. Each correlation coefficient was 0.68 and 0.82, respectively, which means CE was more accurate than Extem-Fibtem A10. We also found 75, and 50 of CE were referred to 10, and 5×104/μl of platelet counts, respectively. CE was a new criterion2) and can reflect platelet aggregation precisely. The calculation formula of CE = (100×EXTEM)/(100-EXTEM)− (100×FIBTEM)/(100-FIBTEM). But they had not reported how much values were the normal range yet. 
Conclusions:
CE was more accurate than Extem-Fibtem A10. We also detected the border line values of CE, 50~75 were almost corresponded to platelet count 50,000~100,000/μl.
References:
1）Japanese cardiovascular anesthesia 2015; 19: 49-54
2）Anesth Analg 2015;121:868-78




01 / Which measurements calculated by rotation thromboelastometry were more accurate for platelet counts, Extem-Fibtem or Clotting elasticity?