Sonoclot coagulation analysis: new bedside monitoring for determination of the appropriate heparin dose during haemodialysis.

BACKGROUND Thrombotic and haemorrhagic complications affect cardiovascular morbidity and mortality in haemodialysis patients. We investigated whether a new bedside Sonoclot analysis is useful for determining an appropriate heparin dose during haemodialysis. METHODS Twenty-two haemodialysis patients (15 males and seven females) treated with unfractionated heparin were recruited. Sonoclot parameters, including activated clotting time (ACT), clot rate (CR), time to peak (TP) and peak amplitude (PA), were examined before and after haemodialysis, coupled with conventional coagulable variables, platelet count and fibrinogen level. Some indices were determined and verified to control heparin dose. Thrombotic and haemorrhagic complications were observed for 3 months. Sonoclot analysis was subsequently performed before initiation, 1 h later, 2.5 or 3 h later (before cessation of heparin infusion), and at the end of haemodialysis. RESULTS Both CR and PA were positively correlated with platelet count and fibrinogen level. Sonoclot parameters except for PA were significantly correlated with heparin dose. Heparin dose was reduced without causing complications in 12 patients with DeltaACT >/=40 s and/or CR after haemodialysis (CRpost) <20 U/min. Thrombotic complications occurred in five patients who had CRpost >30 U/min. ACT and TP increased during heparin treatment. ACT was reversed but TP did not change after cessation of heparin. CR significantly decreased after initiation of heparin and was reversed, although not completely, after cessation of heparin. PA showed no significant changes during haemodialysis. CONCLUSIONS Sonoclot analysis can monitor accurate coagulable states and determine an appropriate heparin dose during haemodialysis.