THROMBOELASTOGRAPHY FOR THE PREDICTION OF BLEEDING AFTER TRANSPLANT RENAL BIOPSY

The ability of prebiopsy coagulation assays to predict mild postbiopsy bleeding was evaluated in renal transplant patients undergoing renal allograft biopsy (N = 120). The coagulation assays studied included th e bleeding time, prothrombin time, partial thromboplastin time, platel et count, and thromboelastograph (TEG). Coagulation results were defin ed as abnormal if they fell outside the established normal reference r ange, Bleeding was defined as a drop in the hematocrit equal to or mor e than 4 points 6 h after the procedure or ultrasound evidence of a ne w perirenal hematoma. Overall, 21% of patients showed evidence of mild bleeding. Of those who bled, 78% had normal results on all coagulatio n tests, indicating that most mild bleeding was not associated with co agulation abnormalities. Of the assays tested, only abnormal TEG:angle (P < 0.01) and TEG:k (P < 0.04) values were associated with an increa sed risk of bleeding. Bleeding times were not predictive of an increas ed risk of postbiopsy bleeding; five patients had abnormal bleeding ti mes ranging from 10 to 20 min of whom only one bled, All prothrombin t ime, partial thromboplastin time, and platelet count abnormalities wer e mild (e.g., no prothrombin times longer than 15 s, no platelet count s below 129,000/mu L); none of these assays predicted postbiopsy bleed ing. Other clinical characteristics, including patient age, sex, serum creatinine, blood pressure (if less than 160/90 mm Hg), number of bio psy passes, or renal pathology, did not appear to influence bleeding a fter biopsy. It was concluded that most bleeding after transplant rena l biopsy was not associated with coagulation abnormalities and that th e TEG was the best assay for detecting mild coagulation abnormalities associated with an increased risk of bleeding.