State-of-the-Art Review : Heparin-Induced Thrombocytopenia: A Critical Risk/Benefit Analysis of Patients in Intensive Care Treated With R-Hirudin

Open Access
Publisher Website
Google Scholar
Abstract
Patients in intensive care may be at high risk of in vivo platelet activation because comorbid conditions, such as infections, septicemia, shock, disseminated intravascular co agulation, and cancer represent procoagulant states. Hyperre activity of platelets with or without a decline of cell count may result in thromboembolic complications potentially associated with the phenomenon of heparin-induced thrombocytopenia. We analyzed the data of 10 patients highly suspected of having heparin-induced thrombocytopenia during their intensive care treatment of 29 plus or minus 22 days. In seven patients, throm bocytopenia coincided with thromboembolic complications. Six patients had additionally undergone fibrinolytic therapy before starting activated partial thromboplastin time-adapted alternative anticoagulation with r-hirudin. In three patients, the platelet count decreased without a clinical manifestation. of heparin-induced thrombocytopenia. R-Hirudin treatment moni tored by activated partial thromboplastin time and prothrombin time (PT) was effective and safe. The target value for activated partial thromboplastin time was a twofold prolongation. In four of five patients with deep venous thrombosis, a partial recana lization of the lower extremity could be achieved. Three pa tients with pulmonary embolism associated with deep venous thrombosis in two cases and in one additional case with an acute myocardial infarction did clinically profit from fibrino lysis with recombinant tissue plasminogen activator (rtPA) and r-hirudin treatment. Two lethal events probably caused by the underlying multimorbidity could not be prevented. No recur rence of thrombosis occurred, and there were no severe bleed ing complications attributed to r-hirudin treatment. Platelet counts were significantly reduced on day 9.4 plus or minus 6.4 of heparin administration in all cases (>50% decrease related to the initial values) from 224,000 plus or minus 126,000/μL to 96,000 plus or minus 61,000/μL, and increased during r- hirudin treatment to mean values of 224,000 plus or minus 126,000/μL. The heparin-induced platelet activation assay (HIPAA) assay was positive in 8/10 cases, whereas the PF4 enzyme-linked immunosorbent assay showed a positive result in four of eight analyzed cases. In four cases, the assays were concordantly positive. The PF4 enzyme-linked immunosorbent assay was not performed in two cases.

This publication has 2 references indexed in Scilit: