Activated Clotting Time and Haemostatic Complications in Patients Receiving ECMO Support: A Systematic Review

Area of Science:

• Critical Care Medicine
• Cardiovascular Surgery
• Hematology

Background:

• Extracorporeal membrane oxygenation (ECMO) necessitates systemic anticoagulation, commonly with unfractionated heparin (UFH), to prevent circuit thrombosis.
• Anticoagulation with UFH carries an inherent bleeding risk, requiring vigilant monitoring.
• Activated clotting time (ACT) is frequently used to monitor UFH anticoagulation, but its efficacy in ECMO patients is debated.

Purpose of the Study:

• To systematically review existing evidence on the association between ACT monitoring and haemostatic complications (bleeding and thrombosis) in patients undergoing ECMO.
• To evaluate the reliability of ACT as a monitoring tool for UFH anticoagulation in the context of ECMO.

Main Methods:

• A systematic literature review was conducted using Scopus and PubMed databases.
• Studies included patients receiving ECMO support with UFH anticoagulation monitored by ACT.
• Data on bleeding events, thrombosis, and mortality were extracted and analyzed.

Main Results:

• Out of 3536 identified publications, 30 studies involving 2379 patients were included.
• Most studies (13/23) found no significant association between ACT values and hemorrhage.
• Pooled data indicated a 49% rate of major bleeding, 25% rate of thrombosis, and 51% in-hospital mortality.

Conclusions:

• The optimal anticoagulation monitoring strategy for ECMO remains unclear.
• Current evidence does not support a significant relationship between ACT levels and haemostatic complications in ECMO patients.
• ACT is likely an unreliable tool for monitoring UFH anticoagulation in ECMO, warranting investigation into alternative methods.