Abstract Number: PB0489
Meeting: ISTH 2020 Congress
Background: The rotational thromboelastometric (ROTEM) parameters INTEM clotting time (CT) and HEPTEM-CT are used peri-operatively in cardiopulmonary bypass (CPB) surgery to monitor heparin. Higher protamine-to-heparin dosing ratios (PH-ratio) are associated with paradoxical increases in both INTEM and HEPTEM-CT values, with HEPTEM-CT frequently exceeding INTEM-CT (I/H-CT ratio < 1.0). Normal protamine dosing occurs at PH-ratio of 0.8-1.0 (>1.0 is considered high-dose). Protamine itself has anticoagulant effects by inhibiting platelet function, FVa, and thrombin generation.
Aims: Investigate the PH-ratio and use of plasma post-CPB in bleeding patients with HEPTEM-CT > INTEM-CT.
Methods: We reviewed ROTEMs performed at our institution between March 2018-March 2019. Forty patients undergoing CPB were found to have I/H-CT ratios < 1.0. Of those, twenty-eight were temporally associated with protamine administration. Data regarding total protamine and heparin dose, the PH- and I/H-CT ratios, and intraoperative plasma use were collected.
Results: Among the twenty-eight patients with IH/CT-ratio < 1.0 temporally associated with protamine, twenty-one (75%) received high-dose protamine (PH-ratio >1.0). The mean PH-ratio was 1.26 (median 1.25), while the mean I/H-CT ratio was 0.91 (median 0.93). Twelve patients (43%) received plasma resulting from ROTEM abnormalities, receiving a mean of 2.17 units (447 mL) plasma in the period immediately following protamine.
Conclusions: Most patients with I/H-CT ratio < 1.0 received high-dose protamine, reinforcing the association between increasing PH-ratio and prolongation of HEPTEM-CT compared to INTEM-CT. As HEPTEM-CT should be equal to INTEM-CT in the absence of heparin, aberrant results such as those seen here may be misinterpreted as a coagulopathy and result in additional protamine administration and/or transfusion of unnecessary plasma for protamine induced coagulopathy/bleeding. In our institution, 43% of patients with IH/CT-ratios of < 1.0 received additional FFP as a direct result of ROTEM results. Understanding protamine's effects on ROTEM and the adoption of more modest protamine dosing regimens may result in fewer unnecessary transfusions.
To cite this abstract in AMA style:Webb C, Sarode R, Compton F, Welder D, De Simone N. Overdosing of Protamine during Cardiopulmonary Bypass May Increase Use of Unnecessary Blood Product Administration when Monitoring with ROTEM [abstract]. Res Pract Thromb Haemost. 2020; 4 (Suppl 1). https://abstracts.isth.org/abstract/overdosing-of-protamine-during-cardiopulmonary-bypass-may-increase-use-of-unnecessary-blood-product-administration-when-monitoring-with-rotem/. Accessed December 3, 2021.
« Back to ISTH 2020 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/overdosing-of-protamine-during-cardiopulmonary-bypass-may-increase-use-of-unnecessary-blood-product-administration-when-monitoring-with-rotem/