Individual responses to heparinization for extracorporeal circulation

Area of Science:

• Cardiovascular Surgery
• Anesthesiology
• Pharmacology

Background:

• Heparinization protocols for extracorporeal circulation (ECC) may be suboptimal due to wide variations in individual patient responses.
• Effective anticoagulation management is critical during open cardiac operations requiring ECC.

Purpose of the Study:

• To investigate the variability of individual heparin response during ECC.
• To evaluate the efficacy of the Blood Activated Recalcification Time (BART) test for monitoring heparinization.
• To assess the impact of BART-guided heparin management on anticoagulation and protamine reversal.

Main Methods:

• Thirty-nine patients undergoing open cardiac surgery with ECC were anticoagulated using a standard protocol.
• The Blood Activated Recalcification Time (BART) test was employed to monitor the coagulation state intraoperatively.
• Heparin dosage adjustments were made based on BART results.

Main Results:

• Significant variations in heparin dose-response and heparin activity decay were observed among patients.
• No patients were found to be under-heparinized.
• Many patients exhibited prolonged BART times, indicating effective anticoagulation without the need for additional heparin doses.
• BART monitoring facilitated a reduction in total heparin dosage by allowing the elimination of incremental doses up to 180 minutes of ECC.
• Protamine reversal was adequate in all patients, irrespective of their individual heparin response.

Conclusions:

• Individual heparin response during ECC is highly variable.
• The BART test is a valuable tool for monitoring intraoperative coagulation status and guiding heparinization.
• BART-guided heparin management can optimize anticoagulation, reduce total heparin dose, and ensure safe protamine reversal during ECC.
• Rapid point-of-care coagulation tests can inform the development of improved heparinization strategies for ECC.