Recurrent heparin-induced thrombocytopenia due to heparin rinsing before priming the machine in a hemodialysis patient: A case report.

Heparin has remained the most commonly used anticoagulant for patients undergoing hemodialysis. It is usually safe to use but can have severe adverse effects in some cases. Heparin-induced thrombocytopenia (HIT) is a life-threatening complication of exposure to heparin. It results from an autoantibody directed against endogenous platelet factor 4 (PF4) in complex with heparin, which activates platelets and can cause catastrophic arterial and venous thromboses. Here, we present the case of an 80-year-old woman with a recent diagnosis of chronic renal failure who developed acute HIT (platelet count nadir, 15 × 109 /L) on day 7 of hemodialysis performed with routine heparin anticoagulation, who despite subsequent heparin-free hemodialysis (with argatroban and warfarin) developed recurrent HIT (complicated by acute cerebral infarction) on day 11 that we attributed to "rinsing" of the circuit with heparin-containing saline (3,000 units of unfractionated heparin, with subsequent saline washing) performed pre-dialysis as per routine. After stopping heparin rinsing, the platelet count recovered completely, without further thrombotic or other sequelae. Our experience indicates that for patients with acute HIT, besides the well-known practice of using non-heparin anticoagulation during dialysis and avoiding heparin "locking" of dialysis catheters, it is also important to avoid inadvertent rinsing of the circuit with heparin during preparation for hemodialysis.