PERIOPERATIVE HYPERCOAGULABILITY IN UREMIC PATIENTS - A VISCOELASTIC STUDY

Study Objective: To examine whole blood coagulation in uremic patients presenting for surgery with the thromboelastogram and the Sonoclot an alyzer. Design: Prospective, observational study. Setting: Operating r ooms of a university-affiliated hospital. Patients: 30 ASA physical st atus II and III patients with chronic renal failure, and 30 age-matche d and gender-matched patients with normal renal function, presenting f or elective surgery. Interventions: Blood sampling for thromboelastogr aph and Sonoclot analysis immediately after anesthetic induction, prio r to surgical incision. Measurements and Main Results: Thromboelastogr aphic indices of coagulation, reflecting coagulation factor function ( R time), fibrinogen-platelet interaction (K time and alpha angle), and qualitative platelet function (maximum amplitude) were hypercoagulabl e in the uremic group compared with the control group (p < 0.05). Fibr inolysis (%) teas decreased in the uremic group (p < 0.05). Fibrin for mation (initial slope) and platelet function (time to peak) of the Son oclot trace also were hypercoagulable in the uremic group (p < 0.05). Conclusions: The high incidence of arteriovenous graft and fistulae th romboses in uremic patients belies in vitro laboratory evidence of pla telet dysfunction. We have demonstrated perioperative hypercoagulabili ty in uremic patients with viscoelastic measures of whole blood coagul ation. These data suggest that traditional concern for coagulopathy an d platelet dysfunction in uremic patients may require re-assessment in light of this ''pro-thrombotic'' state. (C) 1997 by Elsevier Science Inc. .