Coagulation dynamics and platelet functions in obstructive jaundiced patients

Background:  All of the body systems are affected by increased levels of bilirubin. The aim of this study is to investigate the function of platelets and clotting dynamics in patients with obstructive jaundice. Methods:  Liver function tests, serum CRP, PT, PTT and hemogram were measured in 23 patients with obstructive jaundice. Thromboelastography (TEG) was done for the evaluation of coagulation dynamics, while platelet function assay (PFA 100) was used to evaluate platelet functions. Blood samples were obtained at two occasions, before the drainage and 3 weeks after the relief of the obstruction. Results:  Hypercoagulation was detected in 80% of patients. Maximum strength, elasticity, coagulation indices of the clot were correlated with increased concentrations of direct bilirubin. Although maximum strength of coagulum usually represents increased activity of platelet function, membrane closure times with PFA 100 were found to be prolonged in 30% of patients, reduced values were determined in 17% of patients. No demonstrable effect on coagulation parameters and platelet function were detected after drainage procedures regardless of modality. Conclusions:  Even though there is a general assumption about the increased bleeding tendency in obstructive jaundiced patients, we could not demonstrate reduced clotting activity by measuring with either PFA or TEG. On the contrary we observed tendency for hypercoagulation independent of increased prothrombin times. The most probable cause of this effect is the increased activity of fibrin polymers on platelet membrane.