Clinical Trials

Anesthesiology Projects

Title: A Pilot Study of Thrombin Generation Changes in Neonates Undergoing Placement of a Blalock-Taussig Shunt 
Principal Investigator: Nina Ann Guzzetta, M.D.

A Blalock-Taussig (BT) shunt is a surgically placed synthetic shunt which re-directs systemic blood flow into the pulmonary circulation. It is often placed in neonates with right-sided obstructive cardiac defects in order to increase pulmonary blood flow. In the immediate hours after placement of a BT shunt, it is not infrequent for a neonate to experience an episode of profound hypoxia and even cardiac arrest as a result of clotting of the shunt and subsequent loss of pulmonary blood flow. The state of the clotting system in the immediate postoperative period that precipitates this presumed hypercoagulable state has not been adequately assessed.

Thrombin generation is a critical event in promoting clot formation. A laboratory assay of thrombin generation (Thrombinoscope, Synapse BV, Netherlands) allows a functional overview of clot formation and dissolution by measuring a thrombin generation curve (TGC). Peak thrombin generation as measured by the TGC has been shown to provide an objective measurement of the effectiveness the clotting system, even better than the standard laboratory tests PT and aPTT.

In this investigation, we intend to describe the perioperative changes in thrombin generation, and consequently in clot formation, that occur in neonates undergoing placement of a BT shunt by examining pre- and postoperative thrombin generation curves.