Heparin induced thrombocytopaenia secondary to intraperitoneal heparin exposure

Type II immune-mediated heparin-induced thrombocytopenia (HIT) is reported to occur in 2% of individuals exposed to heparin for more than 4 days [1]. HIT has been well described in haemodialysis patients with a similar incidence to non-dialysis patients [2]. Patients treated with peritoneal dialysis are not routinely exposed to heparin during dialysis, and for this reason a switch from haemodialysis to peritoneal dialysis is often considered if HIT occurs in a hemodialysis patient. Previous studies have demonstrated that intraperitoneal heparin does not produce systemic anticoagulation and it has been suggested that a combination of large molecular weight and negative charge prevent systemic absorption of heparin across the peritoneal membrane [3]. However, it is unclear as to whether the reported lack of systemic absorption across the peritoneal membrane protects against the development of HIT. This is an important consideration because in many units it is standard practice to administer intraperitoneal heparin to prevent fibrin clot formation during episodes of peritonitis. In this case report we describe for the first time, to our knowledge, a case of type II HIT in a peritoneal dialysis patient who received intraperitoneal heparin.