Online Hemodiafiltration

Online Haemodialfiltration HDF is a strategy that that enables high potential of hydraulic and solute permiabilityof synthetic membranes hence they can be properly exploited. The high cost of the fluids in bags that are commercially prepared as well as the improvement of technology of dialysate preparation and fluid filtration has made it possible in recent years for the development of the novel technique known as online HDF.

In this technique a particular amount of freshly prepared ultrapure dialysate is taken daily from daily dialysate inlet line and then processed with several filtration steps before they are used as replacement fluid. With this technique, large amounts of replacement solutions that are relatively inexpensive are made available and HDF can be carried out with a high fluid turnover under the utilization of pre- and post-dilution or even consecutive pre-post dilution in proportions that differ (Yvonne, 2011).

On-line hemodifiltration provides the largest amount when it comes to the purification of blood over very wide molecular weight spectrum that can be achieved with the present existing renal replacement therapies. When it is used with the state of the art dialysis membrane as well as systems of treatment, this biocompatibility of the online HDF is quite high. The online production of the unlimited amount of these sterile dialysate at very low costs has made it possible for its extensive diffusion over the recent years.

In order to achieve efficient convective transport, infiltration rates have to be forced towards the existing physical limits, being cautious about safety of the patient and to the integrity of the system Advantage of Online Haemodialfiltration This mode of treatment has several advantages such as a decrease in mortality and morbidity.

This mode of treatment also means a better hemodynamic stability and better control of blood pressure .with this treatment there is an increase in biocompatibility due to the combined use of ultrapure dialysis fluid, biocompatible membrane and passivation of the membrane through these of proteins coating layer. It also leads to a decrease in systematic inflammatory markers.it makes it possible to remove middle molecules such as [beta]microglobulic. It generally has improved dialysis efficiency for small and middle molecules.

The process leads to an improvement in nutritional status, in the possibility of anemia due to removing erythropoietic inhibitor substances and lessen an inflammatory response and finally an improved lipid layer. The quality of the reinfusion fluid is excellent, and it is guaranteed by the redundancy of the filtration system. Disadvantage of Online Haemodialfiltration Some of the disadvantages of online-HDF are the contamination of water, infusate fluid or dialysate. It leads to the loss of proteins and essential vitamins.

There is also an increased risk of cardiovascular morbidity as a result of an increase in the viscosity of blood. The treatment requires a modification of anticoagulation due to the increase in viscosity of the blood. How it help to prevent hypotension during hemodialysis During hemodialysis, low molecular weight uremic waste products are removed from the blood mainly through the process of diffusion across a membrane however; it is limited in its ability of clearing larger uremic toxins.

However, in online HDF, hemodialysis is combined with hemofiltration whereby there is a high rate of movement of solutes and water from blood to dialysate by means of a convection being influenced by positive hydrostatic pressure. A replacement fluid keeps the fluids of a patient in balance. This combination of techniques leads to a good removal of both large and small molecules from the blood and hence leads to.