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In vitro protamine addition for coagulation assessment using TEG 6s system during cardiopulmonary bypass: a pilot
Koichi Yoshinaga1, Yusuke Iizuka2, Yoshihiko Chiba1
1Department of Anesthesiology and Critical Care Medicine, Jichi Medical University Saitama Medical Center, 1-847, Amanuma-Cho, Omiya-Ku, Saitama-Shi, Saitama, 330-8503, Japan.
General Thoracic and Cardiovascular Surgery
|July 17, 2024
Summary
Adding protamine in vitro to blood samples during cardiopulmonary bypass (CPB) allows for accurate thromboelastography (TEG) assessment. This method correlates well with post-CPB measurements, aiding in early coagulation status prediction.
Area of Science:
- Anesthesiology and Critical Care Medicine
- Hematology
- Surgical Sciences
Background:
- Systemic heparinization during cardiopulmonary bypass (CPB) complicates coagulation monitoring using thromboelastography (TEG).
- Accurate assessment of coagulation status is crucial for managing patients during and after CPB.
- Existing methods for TEG analysis during CPB are limited by heparin interference.
Purpose of the Study:
- To investigate the feasibility of using in vitro protamine addition for TEG analysis during CPB.
- To assess the reliability of TEG 6s system measurements with in vitro protamine during CPB.
- To determine if in vitro protamine addition can predict post-CPB coagulation status.
Main Methods:
- Prospective observational study involving 21 patients undergoing elective cardiac valve surgery.
- In vitro protamine (0.05 mg/mL) was added to heparinized blood during CPB for TEG 6s analysis (Pre).
- TEG parameters were compared with post-CPB measurements after systemic protamine administration (Post).
Main Results:
- Citrated kaolin maximal amplitude (CK-MA) and citrated functional fibrinogen maximal amplitude (CFF-MA) showed strong correlations between Pre and Post measurements (r=0.790, r=0.974).
- Bland-Altman analysis indicated clinically acceptable agreement for CK-MA (10.6% error) and CFF-MA (12.2% error).
- Citrated kaolin reaction time (CK-R) lacked significant correlation between Pre and Post measurements (r=0.328).
Conclusions:
- In vitro protamine addition enables reliable TEG 6s assessment of coagulation during CPB.
- CK-MA and CFF-MA measurements during CPB correlate well with post-CPB values.
- This method may facilitate early prediction of post-CPB coagulation status and guide transfusion decisions.
