Dialysis Compilation

8/10/2019 Dialysis Compilation

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UNIVERSITI TEKNOLOGI MARA

FAKULTI KEJURUTERAAN KIMIA

SEPARATION PROCESS ll (CBE682)

NAME : NURWANI BINTI HUSSIN (2012862664)AMANINA MAHFUZAH BINTI JAMALUDDIN (2012483034)SHAIRAH ADIBAH BINTI HUSAIN (2012852942)

AINUL JAMILAH BINTI AZMAN (2012292622)

GROUP : 5A

ASSIGNMENT : DIALYSIS

DATE : 4 DEC 2014

PROG/CODE : EH242

SUBMIT TO : MDM NURUL ASYIKIN BINTI MD ZAKI


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A. INTRODUCTION

Dialysis is needed when a patients kidneys stop working properly. Dialysis is one form of renalreplacement therapy (RRT) and transplantation is the other. Dialysis will make patients feel better but itdoes not make them feel normal or return the blood test results to normal, as hope will happenwith transplantation. Dialysis is used until transplantation is possible. Dialysis does the job that isnormally carried out by the kidneys. That is, it takes away the substances that the body does not needthat would otherwise build up in the blood and make someone ill. Dialysis also removes salt and waterfrom the body if the kidneys have reduced the amount of urine they are making. (NHS, 2011)

There are two types of dialysis: peritoneal dialysis and haemodialysis. Both methods have theiradvantages and one type may be more appropriate for your child than the other. In both types, theprincipal is the same: a cleaning fluid called dialysate is used to take the impurities, salt and water awayfrom the blood. The impurities pass from the blood into the cleaning fluid. There has to be a barrierbetween the blood and the cleaning fluid for this to happen. In haemodialysis, the barrier is the filter inthe dialysis machine that the blood passes through and in peritoneal dialysis, the barrier is the layer of

cells that lines the abdomen and covers the intestines (peritoneum). (Fresenius Medical Care, 2014)

Haemodialysis Peritoneal dialysis

Takes blood from the body to be filtered Does not take blood from the body to be filtered

Uses a synthetic filter in a dialysis machine to filterblood

Uses the lining of the abdomen (peritoneum) tofilter blood

Is usually done in hospital but can be at home inbigger children

Is flexible as it can be done almost anywhere

Whenever there is plastic inserted into the body (central venous haemodialysiscatheters and peritoneal catheters) , there is a chance of them becoming infected. Also as the kidneysare working so badly, there is a risk of the blood potassium becoming high if care is not taken with diet,and this can make the heart rate abnormal. In the long term, there is a very high risk of cardiovasculardisease, such as heart attacks and strokes, due to high phosphate, BP (blood pressure) and PTH( parathyroid hormone) levels. There is a chance of death for children on dialysis, although this is low atabout one per cent a year. There is also a chance of dying with a transplant, but overall the rate of death

is lower. (NHS, 2011) (Hamilton)
http://www.gosh.nhs.uk/medical-information/procedures-and-treatments/kidney-transplant-practical-information-for-families/http://www.gosh.nhs.uk/medical-information/procedures-and-treatments/peritoneal-dialysis/http://www.gosh.nhs.uk/medical-information/procedures-and-treatments/central-venous-haemodialysis-catheters/http://www.gosh.nhs.uk/medical-information/procedures-and-treatments/central-venous-haemodialysis-catheters/http://www.gosh.nhs.uk/medical-information/procedures-and-treatments/peritoneal-dialysis/http://www.gosh.nhs.uk/medical-information/procedures-and-treatments/peritoneal-dialysis/http://www.gosh.nhs.uk/medical-information/procedures-and-treatments/central-venous-haemodialysis-catheters/http://www.gosh.nhs.uk/medical-information/procedures-and-treatments/central-venous-haemodialysis-catheters/http://www.gosh.nhs.uk/medical-information/procedures-and-treatments/peritoneal-dialysis/http://www.gosh.nhs.uk/medical-information/procedures-and-treatments/kidney-transplant-practical-information-for-families/


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B. PRINCIPLE OF DIALYSIS

There are two types of dialysis: hemodialysis and peritoneal dialysis. In hemodialysis, blood is passedthrough an artificial kidney to clean it. Peritoneal dialysis uses a filtering process similar to hemodialysis,but the blood is cleaned inside the body rather than in a machine. In hemodialysis, blood is removedfrom the body and circulated through an extracorporeal fluid circuit hemodialyzer (outside the body),then returned to the patient. (Rockwell Medical, 2014).The hemodialyzer contains a selectivelypermeable membrane, which is a filter that allows fluids and waste to pass through, but prevents theexchange of blood components, microorganisms and the dead endotoxins. This circuit includes ahemodialyzer, which is where the blood is cleaned. The fluid used to clean the blood (dialysate) flows inthe opposite direction to the blood on the opposite side of the membrane, while waste and extra fluidare removed from the blood and end up in the dialysate by controlling three processes: Diffusion, ultra-filtration and osmosis. (Hamilton)

In this process, toxins and body waste are transported, by a concentration gradient, out of the bloodthrough a membrane into an isotonic salt solution. The membranes used in this case have open pores. Indiffusion dialysis, the potential of a concentration difference is also instrumental for mass transfer butpore-free ion exchange membranes are used in this case. Hence, free strong acids can be recovered byusing anion exchange membranes and free strong bases by using cation exchange membranes.(Hamilton) (Rockwell Medical, 2014)

Reference from web site (BWT Group, n.d.) and (TOLTEC International. Inc, 2006)

The dialysis process is applied for the recovery of free acids or bases from treatment bathsolutions in surface finishing and textile processes. The bath solution is separated in a chamber incounter-current flow and via an ion exchange membrane and is then routed to a second chamber

through which water flows. The free acid or base is able to permeate while the salts are retained.Depending on the process design, up to 95% of the free acid and up to 80% of the base can be recoveredin this way and returned to the production process, thus saving chemicals needed for the finishing bathsor wastewater treatment. (BWT Group, n.d.) However, the important advantage is that processefficiency in production is increased. The individual parameters for the bath solutions are stabilizedwhich results in a constant uniform effect of the bath solution on the work pieces. These aspects haveparticular significance for example in anodizing baths (surface optics) or in alkaline baths for thealuminum chemical milling. (Baxter Renal, 2006)


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Ultra-filtration , also referred to as convection, is fluid flow through the membrane, forced by adifference in pressure on the two sides of the dialyzer (pressure gradient). The machines are generallycontrol the volume of fluid removed from the patient directly and allowing pressure to change.Volumetric control is generally achieved either by controlling the flow of dialysate in and out of thedialyzer at different rates with two flow controllers, or by having equal flow rates in and out of the

dialyzer and removing fluid between these equal flows. Volumetric control allows the doctor to takeadvantage of more effective "high flux" dialyzers, which allow a great deal of fluid movement with verylittle pressure differences. (TOLTEC International. Inc, 2006)

Reference from (TOLTEC International. Inc, 2006)

Osmosis is the net movement of water across a selectively permeable membrane driven by adifference in the amounts of solute on the two sides of the membrane. In dialysis, this refers not towater movement across the hemodialyzer membrane, but across cell membranes within the body-eitherfrom within the red cells to the blood plasma, or from within cells of the various tissues in the body (likemuscles) to interstitial fluid (the fluid in between cells). Sodium profiling, as described in the diffusion

section, can be used to increase the rate of osmosis early in the treatment by increasing the sodiumlevel of the plasma (TOLTEC International. Inc, 2006)

Reference from (TOLTEC International. Inc, 2006)


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C. Equipment involves in dialysis

The process of haemodialysis pumps the patients blood against dialysate may be generated by thedialysis machine or at a central location. Commonly, the dialysis machine composed of pumps, monitors,and alarms that allow safe proportioning of dialysate. Several components of proportioning ensure safedialysate that is monitored by a series of alarms, pumps, and monitors. Below are the main componentsof dialysis device. (ASN, 2013)

Deaeration

Figure 1.1: Deaeration pathway

Heating treated water to 85C followed by cooling prior to proportioning can also de-gas purified water.Water heated to physiologic temperatures is subjected to negative pressure to remove any air. Air in thewater can interfer e with dialysate flow and cause air trapping

Dialysate proportioning and conductivity

Figure 1.2: Conductivity cellTo ensure that the proper mixing of heated and treated water to produce the appropriate dialysatesolution.


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Monitors, alarms, and conductivity

Figure 1.3: Alarm device

PH: Range between 6.8 7.6

Temperature: 35 42C

If temperature drop, it can cause shivering but if temperature rise, protein will denature.

Conductivity: 12 16mS/cm (millisiemens per centimeter).

If the conductivity exceeds the limits, the alarm will stop the dialysate flow.

Ultrafiltration: Volumetric and flow-sensor control

Volumetric based ultrafiltration

Figure1.4: Volumetric control

Ultrafiltration is a process where the fluid is being removed by body which volume hasbeen measured accurately. Usually used balancing chamber that composed of 2 compartmentsseparated by a flexible membrane. One side allow the movement of fresh dialysate in, while theother allows spent or used dialysate out. Valve has been connect to allow the fluid to enter one


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side of the chamber then pushes an equal amount of fluid out of the other side of the chamber.One chamber has been filled with used dialysate then pushes fresh dialysate to the dialyzer,while the other chamber is filling with fresh dialysate and pushes used dialysate to the drain.

Flow control base ultrafiltration

Figure 1.5: Flow control in dialysis

Allow control of dialysate flow since there is flow sensor at the inlet and outlet dialyzer. A post-dialyzerUF pump removes fluid at an UF rate calculated by the dialysis machine.


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D. Membrane Materials

As the dialysis is based on diffusion during which the mobility of solute particles between twoliquid spaces is restricted, mostly according to their size. Therefore, size restriction is achieved by using aporous material, usually a semi-permeable membrane called dialysis membrane. This membrane ispermeable only for particles below a certain size. Synthetic and natural membranes are commonly usedfor filtration applications. Membrane materials most often used include regenerated cellulose, celluloseacetate, polysulfone, polycarbonate, polyethylene, polyolefin, polypropylene, and polyvinylidenefluoride.

Cuprophane dialysis membrane (Seattle Artificial Kidney Supply Company, ultrafiltration of 0.27ml/hr/in 2) is a regenerated cellulose membrane made by the cuprammonium process. The material wasconditioned for use by soaking it for siz days in several changes of distilled water to remove all additives(~13% by weight, consisting primarily of urea, diethylene glycol and glycerol) Copolyether-estermembranes that are based on polyoxyethylene glycol were prepared by a modified solutionpolymerization reaction. The copolyether-hydrocarbon membrane is based on polyacrylonitrile andpolyoxyethylene glycol while polypeptide membrane is based on polysacrosine. The polyethylene/NVPmembrane was prepared by radiation grafting N-vinyl pyrrolidone onto polyethylene film. Two modifiedcellulose membranes, Cuenophane and Cadophane were prepared by regenerating cellulose fromcupriethylenediamine-hydroxide and cadmiumethylene-hydroxide. Nephrophane is a regeneratedcellulose membrane made by the sodium cellulose xanthogenate process. This material has been post-treated by a special stretching technique and uses sorbitol and glycerin as additives to the slurry fromwhich the membrane is case. DVF membranes that is also the Union Carbide membrane are fibrereinforced cellulose membranes.

The regenerated cellulose from cotton as the cotton linters are dissolved in a solution andspread into flat sheets or extruded into tubes. The material is treated with glycerin to prevent the poresfrom collapsing and air dried at a certain temperature and pressure to form a rigid membrane. Thiscellulose membrane has a symmetric pore structure which allows small molecules to migrate in eitherdirection, making it ideal for experimental purposes.

Nowdays, more than 30 different polymers or polymer blends are used as materials for dialysismembranes. They can be categorized following the scheme of a family tree of haemodialysismembranes. The trunk represents membranes from regenerated cellulose, major branches show eithersynthetically modified cellulose membranes or membranes manufactured from synthetic polymers. Asthe latter are standardly hydrophobic, small branches elucidate the technique on how these materialshave been rendered partially or completely hydrophilic.

However, complications may arise when membranes only comparing and following their

polymer names, such as polysulfone, polyacrylonitrile or polyamide. Membranes with the same polymernames may differ in their haemocompatibility, flux properties and adsorption characteristics due tovarying polymer compositions. Adsorption of proteins like beta 2-microglobulin, fibrinogen andcoagulation factors, complement proteins, or hormones like parathormon and erythropoietin aredifferently adsorbed by dialysis membranes and thus adsorption contributes to the removalcharacteristics. Of central interest for membrane development and application is the question of howthese membranes can be sterilized, as a series of patient adverse reactions has been attributed to thedialyzer sterilization procedures. Apart from the cellulosic membranes Cuprophan and Hemophan, the


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majority of membranes cannot be sterilized by steam, as these materials degrade when exposed toabove their class-point temperature. Finally, future aspects of modern membrane development shouldnot neglect the needs of patient populations with specific blood properties, such as diabetics.


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E. APPLICATION OF DIALYSIS: HEMODIALYSIS

Separation process by using membrane has become a way out to solve a separation problem in

industries. Especially biotechnological and pharmaceutical industries which involving many fragile or

sensitive heat chemical substances. (W.Rousseau, 1987) This is because, separation using membrane

does not need any heat but only need power supply to run the machine. The membrane has been

designated in various type according to their function. Separation process by using membrane can be

classified into gas diffusion in porous solid, dialysis, gas permeation in a membrane, reverse osmosis,

ultrafiltration, microfiltration and gas permeation chromatography. (Geankoplis, 2003) Every

classification of membrane processes has difference mechanism. For example, in the dialysis, small

solutes in one liquid phase diffuse readily because concentration differences through a porous

membrane to the second liquid phase.

Figure 1 : Hemodialysis machine

Many application had involved the dialysis in chemical processing separation such as separation

of sulphuric acid from nickel and copper sulfates in aqueous form, food processing and artificial kidney.

The artificial kidney or hemodialysis is the most common application of dialysis in our daily life.

Hemodialysis is mainly for those who suffering from kidney failure and has been practiced since 1960s

(Treatment Methods for Kidney Failure : Haemodialysis, 2006) . Healthy kidney clean the blood by

removing excess fluid, minerals, and wastes. They also make hormones that keep bones strong and

blood healthy. When kidneys fail, harmful wastes build up in our body, resulting to blood pressure may

rise, and body may retain excess fluid and not make enough red blood cells. When this happens,

treatment is needed to replace the work of failed kidneys which called as hemodialysis.


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Figure 2: Concentration gradient in blood and dialysate

Hemodialysis is a diffusion-driven process where the component diffuse through a membrane

due the difference in concentration between dialysate and permeates sides of the membrane.

(Separation Through Dialysis Model ID: 258) The process is affected by the temperature, viscosity and

mixing rate of the solution. (The Dialysis Process, 2009) In the process, small-molecular-weight

metabolic waste products are removed from a patients blood by dialytic transfer across a membrane

that is impermeable to normal blood proteins. The dialysate is formulated to normalize blood

electrolyte concentrations and acid-base balance by dialytic exchange between blood and dialysate.

Fluid balance is restored by superimposing a transmembrane hydrostatic pressure gradient.

(W.Rousseau, 1987)

Figure 3: Component of dialyzer

Membrane materials used in the hemodialysis commonly fibers based on synthetic and natural

membrane that stack in a layer. The choice of membrane for a particular application is dependent on

both separation required and the environment in which the membrane is to be operated. Below is the

table of membrane used the dialysis and its manufacturer. (W.Rousseau, 1987)


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Membrane material Manufacturer

Regenerated cellulose Asahi Medical Co. Tokyo Japan

Enka AG, Wuppertal, West Germany

Terumo Corporation, Tokyo Japan

Cellulose acetate Asahi Medical Co. Tokyo Japan

CD Medical, Miami, Florida

Ethylene-polyvinyl alcohol Kuraray Co. Osaka, Japan

Polyacrylonitrile Hospal, Lyon,France

Polycarbonate Gambro, Ab Lund Sweden

Polymethylmethacrylate Toray Industried Inc, Tokyo Japan

Polyperfluoro E.I.Du Pont de Nemours, Wilmington, Delaware

polysulfone Fresenius AG. Bad Homburg, West GermanyTable 1: Dialysis Membrane material (W.Rousseau, 1987)

Two needles are used to accessing or connecting the flow by putting one needle to a tube that

made the blood flow into one side of the filter in the machine. All waste and fluid in blood was pushed

to the other side by passing through a membrane or dialyzer for example cellulose acetate which is

consist of millions of hollow fibers and diffuse in the dialysate. All the larger cells like red blood cell

cannot pass through the membrane and stay behind. Cleaned blood then back into the body by the

other needle. The dialysate is cannot be reusable and thrown away after one using. (How does dialysis

clean my blood?)

Figure 4: Blood flow in hemodialysis


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F. REFERENCES

1. ASN. (2013). ASN DIALYSIS CURRICULUM.Dialysis , 1-30. 2. Baxter Renal. (2006, May 1). How dialysis work . Retrieved November 29, 2014, from

http://www.renalinfo.com/us/treatment/end_stage_kidney_failure/dialysis/how_dialysis_works.html

3. BWT Group. (n.d.). Diffusion dialysis . Retrieved 2014, from fumatech:http://www.fumatech.com/EN/Membrane-technology/Membrane-processes/Diffusion-dialysis/

4. Fresenius Medical Care. (2014). Helping you live a better life on dialysis . Retrieved 2014, fromDialysis: http://www.ultracare-dialysis.com/treating-kidney-failure/about%20dialysis.aspx

5. Geankoplis, C. J. (2003). Transport Process and Separation Process Principles. Pearson.

6. Hamilton, R. W. (n.d.). Principles of Dialysis: Diffusion, Convection, and Dialysis Machines. 2-3.

7. How does dialysis clean my blood? (n.d.). Retrieved from Life Options Rehabilitation Program:http://lifeoptions.org/catalog/pdfs/pics/pic2/pic2_05.pdf

8. NHS. (2011, November). Great Ormond Street Hospital for Children . Retrieved November 2014,from Dialysis: http://www.gosh.nhs.uk/medical-information/procedures-and-treatments/dialysis-an-introduction-to-dialysis/

9. Rockwell Medical. (2014). Dialysis . Retrieved 2014, from Therapeutic Focus:http://www.rockwellmed.com/therapeutic-chronic-kidney-disease-dialysis-hemodialysis.htm

10. Separation Through Dialysis Model ID: 258. (n.d.). Retrieved from COMSOL Inc.:http://www.comsol.com/model/separation-through-dialysis-258

11. The Dialysis Process. (2009). Retrieved from Membrane FIltration Products, INC:http://www.membrane-mfpi.com/home/dialysis_process

12. TOLTEC International. Inc. (2006). How Hemodialysis (Dialysis) Works . Retrieved November2014, from http://www.toltec.biz/how_hemodialysis_works.htm

13. Treatment Methods for Kidney Failure : Haemodialysis . (2006, December). Retrieved fromNational Kidney and Urologic Diseases Information Clearinghouse (NKUDIC):

http://kidney.niddk.nih.gov/Kudiseases/Pubs/hemodialysis/index.aspx14. W.Rousseau, R. (1987). Handbook of Separation Process Technology. Wiley.

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