Quantitation of platelet preservation with prostanoids during simulated bypass

Area of Science:

• Cardiovascular Surgery
• Hematology
• Biomaterials Science

Background:

• Blood-synthetic surface interactions during cardiopulmonary bypass (CPB) lead to adverse platelet alterations.
• These alterations can increase blood loss following open cardiac surgery.
• Temporary inhibition of platelet function may mitigate these changes.

Purpose of the Study:

• To quantify platelet functional and structural alterations during simulated extracorporeal circulation (SEC).
• To compare the efficacy of Iloprost (ZK) and Prostaglandin E1 (PGE1) in inhibiting these alterations.

Main Methods:

• Fresh heparinized human blood was recirculated in a circuit with silicone rubber components and a membrane oxygenator for 2 hours.
• Simulated extracorporeal circulation (SEC) was performed with and without Iloprost (ZK) or PGE1.
• Platelet counts, mean platelet volume, and platelet aggregation responses to epinephrine and thrombin were measured.

Main Results:

• Uninhibited blood recirculation significantly decreased platelet counts and mean platelet volume, while increasing dispersion.
• Both Iloprost (ZK) and PGE1 significantly preserved platelet counts compared to no drug.
• Platelets recirculated with PGE1 showed reduced aggregation responses compared to those merely incubated with PGE1.

Conclusions:

• Platelet inhibition with Iloprost (ZK) or PGE1 during simulated extracorporeal circulation preserves platelet counts and reduces structural alterations.
• PGE1's effectiveness may be reduced by the extracorporeal circuit itself.
• Further optimization of platelet inhibition strategies is needed for CPB.