**2.2.1 Dialyzer reactions**

254 Technical Problems in Patients on Hemodialysis

**2.1.2 Complications resulting from manual setup of the machines or not following the** 

Despite the technological developments in hemodialysis machine, some complications arise due to failure to follow their instruction manuals or setting the alarm limits manually by individuals (Davenport, 2006). For example, one of the errors is to set up artery tubing which does not fit the diameters of the blood pump. This may result in hemolysis by increasing the pre-pumping pressure. Another error occurs when lowering the temperature of the dialysate especially in patients with intradialytic hypotension. In such a case when the hemodialysis machine is reset to stop the alarm, the temperature changes may go unnoticed even at very high or low levels due to a problem in the machine. Very low temperatures make the patient feel cold and very high temperatures may cause serious hemolysis. Most of the hemodialysis machine can automatically perform disinfection through heat or chemicals, but if the user manually restricts the disinfection process, this may cause hemolysis and the resulting symptoms as some of the compounds used in disinfection cannot be removed adequately. In some instances, the venous needle comes loose, but the hemodialysis machine cannot sense this and give the necessary alarm in time, or when the venous alarm limits are changed or the alarm is disabled by the user, an abundant loss of blood from the patient may not be sensed. Considering the above mentioned complications, it would be advisable not to disable the alarm systems of the hemodialysis machine or in cases of necessity to employ close

In a recent study, the effect of the age and maintenance status of a hemodialysis machine on the satisfactoriness of dialysis was examined. The study showed that technical maintenance of the machines in regular intervals had a significant effect on the efficacy of the hemodialysis therapy (Azar, 2009). Therefore, it should remembered that in order to reduce the number of complications and to give the patient the targeted dose of dialysis, calibrations and service maintenance of hemodialysis machine should be regularly made, the machines should be used according to their instruction manuals, and as manual adjustments may harm the patient, the

During hemodialysis, the patient's blood passes through many extracorporeal compartments. These include the dialyzer, the blood tubing set, the chemicals used during sterilization of the dialyzer and the dialysate. The dialyzer contains a dialysis membrane and sterilization products used during its manufacturing. Dialyzers come in two geometries as hollow-fiber and parallel plate dialyzers according to their membrane structure. In hollow-fiber dialyzers with thousands of tiny hollow fibers, blood flows into the compartment at one end of the cylinder-shaped case and passes through thousands of tiny capillaries. Dialysis solution flows in the opposite direction of the blood flow around the capillaries. Blood passing through the capillaries is collected in the compartment at the other

Membranes also come in various types with respect to the material used in them; they can be cellulosic, cellulose/synthetic (semi-synthetic), synthetic and bioactive (in dialyzers covered by vitamin E). They can be referred to as being reusable or not and biocompatible or not in the terminology. The most commonly used ones are the synthetic membranes

patients in such situations should be monitored closely.

**2.2 Membrane-related complications** 

end of the dialyzer and returned to the patient.

today.(Twardowski, 2008).

**instruction manual** 

monitoring.

Hemodialysis-related anaphylactoid reaction was first reported in 1975. A well-documented prospective study on its incidence is not available. However, according to the data from the Food and Drug Administration, a severe hypersensitivity reaction was reported in 3.5 of 100.000 dialysis sessions in 1982 (Ebo et al., 2006). Such reactions consisted of a series of incidences involving both anaphylactic reactions and reactions with unknown causes. The classification made by Daugirdas JT and associates is the one most commonly used for these reactions. The classification involves Type-A (hypersensitivity) reactions and Type-B (nonspecific) reactions (Daugirdas & Ing, 1988).
