A prospective pilot study of platelet function and its relationship with postoperative bleeding in pediatric cardiac surgery.

BACKGROUND: Postoperative bleeding is a major problem in pediatric cardiac surgery with cardiopulmonary bypass (CPB). It recognizes a multifactorial cause, inclusive of coagulation factors consumption, hyperfibrinolysis, incomplete heparin reversal, and platelet consumption. Limited information on platelet function is available. This pilot study investigates platelet function changes in pediatric cardiac operations and their relationship with postoperative bleeding.
METHODS: A cohort of 22 patients aged four years or less were prospectively analyzed. Besides the usual coagulation tests, they were studied for platelet function at four points in time: preoperative, arrival in the intensive care unit, first and second postoperative day. Platelet function was measured with multiple electrode aggregometry TRAP-test.
RESULTS: After the cardiac operation there was a non-significant decrease in platelet function, with 36% of the patients demonstrating increased aggregability. Platelet count demonstrated a significant (P=0.001) decrease related to the CPB duration. The International Normalized Ratio (INR) was significantly (P=0.001) increased after the operation. Postoperative bleeding was associated with the degree of thrombocytopenia (P=0.014), the increase in INR (P=0.001), and the prolongation of the activated partial thromboplastin time (P=0.002).
CONCLUSION: In this pilot study, platelet function in pediatric patients undergoing cardiac surgery demonstrates a variable pattern and no association with postoperative bleeding. Confounding factors like age and cyanosis should be addressed with larger patient populations.