RESUMEN
A 48-yr-old patient was admitted to the ICU for cardiogenic shock and acute renal failure after coronary artery bypass graft surgery. A heparin-induced thrombocytopenia (HIT) occurred during haemodialysis with unfractioned heparin (UFH) as the anticoagulant. The dialysers, the circuits and the catheters were recurrently thrombosing and the platelet count decreased to 9 G.L-1 on postoperative day 7. UFH was discontinued. Attempts to substitute UFH with a low molecular weight heparin (LMWH) failed, due to the presence of a high cross-reactivity rate of LMWH with the heparin-dependent antibody. Intermittent haemodialysis without anticoagulation using a predilution of the dialysers failed also and resulted in recurrent clotting. After informed consent of the patient, a new natural heparinoid Orgaran (Org 10172, Organon, Oss Holland) was administered. This agent is a mixture of several non heparin low molecular weight glycosaminoglycans, with proven anticoagulant efficacy, low cross-reactivity with the HIT antibody, and a half-time prolonged over 18-25 hours. The treatment regimen consisted in a i.v. bolus of 40-45 IU.kg-1 prior to each dialysis procedure, performed every two days. The platelet count increased to 200 G.L-1, seven days after discontinuing heparin injection, and remained stable during the administration of Orgaran. No other thrombosis occurred again. Each procedure of four hours duration was monitored with the plasma anti-Xa activity and APTT test. The mean anti-Xa plasma concentrations (0.44 +/- 0.55 IU.mL-1, 30 min after injection of Orgaran) were well correlated with APTT test (r = 0.73, p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)