HEPARIN-INDUCED THROMBOTIC THROMBOCYTOPENIA

OBJECTIVE: To reports a case of heparin-induced thrombotic thrombocyto penia (HITTS) and discuss the incidence, possible mechanisms, complica tions, and treatment for this syndrome. DATA SOURCES: Case reports and review articles identified by MEDLINE from 1980 through 1991. Older a rticles located by manual searches. DATA EXTRACTION: Data were extract ed and reviewed from published sources. Cases were selected on the bas is of case presentation, time of disease onset, pathophysiology of dis ease, and therapeutic options. SETTING: A 600-bed university teaching hospital and an affiliated community hospital. PATIENT: A 36-year-old woman with insulin-dependent diabetes mellitus, sepsis, adult respirat ory distress syndrome, diabetic ketoacidosis, oliguric renal failure d eveloped HITTS and subsequent gangrene of her right arm. INTERVENTION: Immediate cessation of all heparin use and amputation of the patient' s right arm. RESULTS: The patient's condition improved progressively o ver the following 60 days and she was discharged to outpatient care. C ONCLUSIONS: Heparin has been associated with thrombocytopenia and thro mbotic events. tory tests for HITTS are unreliable and the diagnosis i s usually suspected by the clinical presentation of the patient. Plate let counts should be monitored closely during heparin use. In the even t of a marked decrease in platelet count associated with venous or art erial thrombosis, heparin therapy should be stopped immediately. If fu rther anticoagulation is necessary, oral anticoagulants such as warfar in may be used instead. As the onset of warfarin may take several days to become therapeutic, aspirin, dipyridamole, or both may be used eff ectively. Healthcare workers should be aware that in these patients, t he use of even small amounts of heparin can produce catastrophic resul ts.