title: Heparin-induced thrombocytopenia: a critical risk/benefit analysis of patients in intensive care treated with R-hirudin.
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 coagulation, and cancer represent procoagulant states. Hyperreactivity 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, thrombocytopenia 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 monitored 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 recanalization of the lower extremity could be achieved. Three patients 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 fibrinolysis with recombinant tissue plasminogen activator (rtPA) and r-hirudin treatment. Two lethal events probably caused by the underlying multimorbidity could not be prevented. No recurrence of thrombosis occurred, and there were no severe bleeding 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/microL to 96,000 plus or minus 61,000/microL, and increased during rhirudin treatment to mean values of 224,000 plus or minus 126,000/microL. 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.
authors.affiliation: Department of Clinical Hemostaseology and Transfusion Medicine, University of Homburg, Germany.
authors.forename: J F
authors.initials: JF
authors.lastname: Schenk
authors.forename: G
authors.initials: G
authors.lastname: Berg
authors.forename: S
authors.initials: S
authors.lastname: Mörsdorf
authors.forename: B
authors.initials: B
authors.lastname: Stefan
authors.forename: H
authors.initials: H
authors.lastname: Kroll
authors.forename: B
authors.initials: B
authors.lastname: Krischek
authors.forename: G
authors.initials: G
authors.lastname: Pindur
authors.forename: H
authors.initials: H
authors.lastname: Schieffer
authors.forename: E
authors.initials: E
authors.lastname: Wenzel
mesh_terms: D000328:Adult; D000368:Aged; D003422:Critical Care; D005260:Female; D005343:Fibrinolytic Agents / Q000009:adverse effects* / Q000627:therapeutic use; D006493:Heparin / Q000009:adverse effects*; D024764:Hirudin Therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000188:drug therapy; D010314:Partial Thromboplastin Time; D015539:Platelet Activation / Q000187:drug effects; D010976:Platelet Count; D011517:Prothrombin Time; D011655:Pulmonary Embolism / Q000097:blood / Q000150:complications / Q000188:drug therapy; D011994:Recombinant Proteins / Q000627:therapeutic use; D018570:Risk Assessment; D013921:Thrombocytopenia / Q000139:chemically induced* / Q000517:prevention & control; D010959:Tissue Plasminogen Activator / Q000627:therapeutic use; D020246:Venous Thrombosis / Q000097:blood / Q000150:complications / Q000188:drug therapy
chemical_list: D005343:Fibrinolytic Agents; D011994:Recombinant Proteins; D006493:Heparin; D010959:Tissue Plasminogen Activator