Mechanical haemolysis related to the use of tandem dialyzers

Haemolysis is a well-recognized, rare complication of haemodialysis. The most common reasons for haemodialysis-associated haemolysis are chemical contamination, heat or mechanical injury of erythrocytes from occluded or partially occluded (kinked) haemodialysis lines [1–7]. Tandem dialyzers are occasionally used to improve dialysis dose, especially in patients with high muscle mass [8]. The two dialyzers are aligned in series and connected to each other by a simple blood line. Our patient had a partial occlusion (kink) at this blood line, which resulted in severe haemolysis. Since the changes in venous and arterial pressures were different from those noted with partial occlusion of the venous and arterial lines in standard haemodialysis, the problem was not immediately recognized. This case report describes a serious complication of tandem dialyzers that has not been previously reported.