Other causes of obstruction in the vascular circuit that can foster hemolysis include partial occlusion of a vascular catheter (e.g., at its tip, by a thrombus, development of a thrombus at a dialyzer blood port, wide disproportion between the caliber of a dialysis needle or of a cannula (both being too small) and the blood fl ow rate (being too high), malocclusion of a roller pump with its consequent constricting effect on the blood path within the pump segment of an "arterial" blood tubing, impingement of the bevel of an "arterial" needle against the wall of a vascular access, and kinking of a blood tubing.