Thrombocytopenia associated with dialysis treatments

We present a case of a 51-year-old woman who developed thrombocytopenia associated with dialysis treatments. Laboratory values revealed a platelet count of 50,000 or less postdialysis, with recovery of platelet count during her interdialytic period. An extensive work up including infectious serology and heparin-induced thrombocytopenia test was negative. Based on the pattern of thrombocytopenia and negative work-up, it is concluded that her thrombocytopenia was due to her dialysis treatments. We discuss the literature on thrombocytopenia and hemodialysis and postulate that our patient had a reaction to her dialyzer membrane or to the electron beam radiation method used to sterilize her dialyzer.     

Inadvertent postdialysis anticoagulation due to heparin line locks

Large-bore dual lumen in-dwelling venous catheters are used in hemodialysis. These catheters are usually locked with heparin after the treatment. This study addressed the underappreciated postdialysis coagulopathy that can result. Thirty-six patients were included: 7 dialyzed through arterio-venous fistulae, 29 through in-dwelling venous catheters. The latter group was further subdivided according to whether they received heparin or heparin-free dialysis. To assess the heparin lock, a full-dose heparin lock as well as a much weaker heparin lock and a citrate lock were used. To assess the coagulopathy, blood was taken 1 hr after dialysis. The activated partial thromboplastin time (APTT) and anti-Xa level was measured. Additionally, 6 venous catheters were removed and the amount of fluid expelled upon locking with saline was measured. Clotting from the patient group with arterio-venous fistulae was normal following dialysis. The patients with in-dwelling venous catheters and heparin locks had significantly deranged clotting; 6 out of 10 patients had abnormal APTT results. All patients with catheters, heparin-free dialysis, and heparin locks had deranged clotting (7 out of 7). The rate decreased significantly when heparinized saline was used as a lock. A subset of patients had a citrate lock rather than a heparin lock; the clotting results normalized in all but one patient. An in vitro study demonstrated immediate leakage of fluid from the end of the ports upon locking. Significant postdialysis anticoagulation can occur after dialysis, which can be attributed to the heparin line locks. This risk is considerably reduced when a citrate lock is used instead.     

Heparin leak from a hemodialysis catheter causing major bleeding,ultimately leading to transplant rejection and death

Leakage of hemodialysis catheter‐locking solutions into the circulation has been reported in in vitro and in vivo studies, although there have been few reports of serious clinical adverse events. We describe a case of heparin leak from a hemodialysis catheter, which caused significant clinical bleeding requiring multiple transfusions and may have ultimately been responsible for the patient's death after transplantation.     

Efficacy of Heat Disinfection With the Aksys Personal Hemodialysis System

The first objective of this study was to validate the use of water at 85°C ± 5°C to achieve high-level disinfection of a clean-in-place extracorporeal dialysis circuit. The second objective was to demonstrate that applying this hot water method to the entire fluid pathways of a newly designed dialysis instrument, including an integral reverse-osmosis membrane, routinely allowed the production of back-filtered dialysate meeting the U.S. Pharmacopeia (USP) standard for the water for injection (WFI). In a first study, six dialyzers were inoculated with P. aeruginosa, incubated, and subjected to 75°C water for 30 minutes. No organisms could be recovered from the experimental dialyzers nor from three negative controls, but they were recovered from three positive controls. In a second study, the carbon tanks in the water inlet line and the dialysate tank were both inoculated with massive amounts of dialysis water-adapted Gram-negative organisms, followed by seven dialysis treatments using bovine blood, where the fifth and sixth procedures were separated by 2 idle days and the sixth and seventh procedures were separated by 3 idle days. In addition, the bovine blood used in each treatment was highly contaminated. In every case, the back-filtered dialysate met the WFI standard. From the above results we conclude that a hot water disinfection process is efficacious in reducing even grossly exaggerated contamination in the Aksys personal hemodialysis system to the point where it can produce water and dialysate that greatly exceed the Association for the Advancement of Medical Instrumentation (AAMI) standards and priming and rinse-back solution (back-filtered dialysate) that meets the USP standard for WFI.