abstract
- OBJECTIVE: Despite controversy about whether peripheral and central venous catheters should be locked with heparin to prevent catheter-associated clotting, the practice is widespread. We describe a severe side effect of the practice: a case of heparin-induced thrombocytopenia occurring with catheter flushes using unfractionated heparin (UFH) in a 10-month-old boy successfully treated with danaparoid. Patient: A preterm-born patient (33 wks gestational age, birth weight 1200 g) suffering from VACTERL syndrome was repeatedly treated with UFH in the context of several invasive procedures. On day 310 of age, a central venous catheter was inserted to provide total parenteral nutrition. The central catheter was flushed with a continuous infusion of UFH at 100 U/day, and a decrease in platelet counts from 150,000/&mgr;L (on day 310 of age) to 45,000/&mgr;L (on day 319 of age) was observed. Clinically suspected heparin-induced thrombocytopenia (HIT) was serologically confirmed by demonstrating HIT antibodies with platelet factor 4/heparin complex specificity. Main Result: Catheter flushing was switched to low-dose danaparoid sodium as a continuous infusion at 15 anti-factor Xa units per day. Two days later, platelet counts recovered. Neither catheter thrombosis nor systemic thromboembolic complications occurred during the follow up period. CONCLUSIONS: Even continuous infusion of low-dose heparin to provide patency of central venous port catheters may trigger the primary immune response of HIT. Low-dose danaparoid sodium, a heparinoid, can prevent in-catheter thrombus formation and allows normalization of platelet counts in acute HIT.