Abstract 17201: TEG R-time as a Comparable Method to aPTT and Heparin Levels in Pediatric Patients on Heparin Therapy

Introduction: Hemorrhage post cardiac surgery continues to be a common morbidity despite the advancement in technology in coagulation diagnostics. Although, activated partial thromboplastin time (aPTT) and FXa function (heparin levels) are commonly used methods, there is often discrepancy in results between the methods. Hypothesis: In this study, we analyzed the use of Thromboelastography (TEG) reaction-time (R-time) as an additional diagnostic method for comparison to help guide blood product management. Methods: In a retrospective study of pediatric patients (N=292) who were given heparin, TEG R-time results along with aPTT and heparin levels were collected from the electronic patient records after the approval from our institution review board. Comparisons were made between the three methods using Pearson r correlations. Correlations between the three methods and bleeding events was also analyzed. Results: There were positive moderate correlations between R-time ≥15 min vs. aPTT ≥50s ( r =0.51), R-time ≥15min, vs. heparin levels ≥0.1 IU/ml ( r =0.54); and aPTT ≥50s vs. heparin levels ≥0.1 IU/ml ( r =0.55). When R-time was ≥15min, 74% of the patients had aPTT ≥50s ( p <0.001) and 81% of the patients had heparin levels ≥0.1 IU/ml ( p <0.001). When aPTT was ≥50s, 78% of the patients had heparin levels ≥0.1 IU/ml ( p <0.001). However, no correlation was found between bleeding events vs. R-time ≥15min, aPTT ≥50s and heparin levels ≥0.1 IU/ml. Conclusions: Correlation between TEG R-time versus aPTT or heparin levels was comparable to the correlation between aPTT versus heparin levels. In conclusion, TEG R-time could be used as an additional diagnostic method to help guide blood product management.