1. Principle of hemodialysis In hemodialysis, the blood of the patient via a tube system, controlled by the dialysis machine, passed through a filter. In this filter are hair-thin capillaries, which consist of a semipermeable membrane and are surrounded by a dialysis fluid. Toxic substances or blood salts can now pass through this semipermeable membrane, so that in this way a concentration balance between the patient's blood and dialysis fluid for the said substances takes place and the blood is cleaned. The dialysis machine itself serves to monitor this process of transporting the blood through a system of pumps, and to determine the composition of the dialysis fluid through which the exchange of substances and the reduction of the patient’s blood volume is achieved.

2. Principle of peritoneal dialysis(PD) Peritoneal membrane(natural filter inside your body—the lining of your belly) to remove wastes and extra fluid from your body. It also restores the normal balance of certain minerals in the blood (electrolytes). In peritoneal dialysis a catheter is implanted into the abdominal cavity. The dialysis fluid fills the belly and pulls out extra minerals and fluids from the bloodstream. After a specified time, the dialysis fluid from the abdomen is drained and the toxic fluids along with excess body fluids are thus removed. These wastes then drain out of the body along with the dialysis fluid into a collection bag. Independent patients are thus offered the possibility to carry out their dialysis at home. TYPE OF PD THERAPY Two type : APD(Automated PD) CAPD(continuous ambulatory PD)

3. APD(AUTOMATED PD): type of therapy which perform while a patient sleeps.

4. APD VS CAPD A significant reduction in peritonitis rates with APD( but no significant reduction in relative risk for patients on APD) APD include continuous cyclical PD (CCPD), intermittent PD (IPD), nightly intermittent PD (NIPD) and tidal PD (TPD) Continuous ambulatory peritoneal dialysis (CAPD) involves performing the PD exchanges manually, whereas automated peritoneal dialysis There is less significant reduction in peritonitis rate In CAPD, the patient must perform at least 4–5 exchanges everyday (APD) is abroad term that is used to refer to all forms of PD employing a mechanical device to assist the delivery and drainage of dialysate.

5. GRAFT OF DIALYSIS The three most common types of access are: Internal arterio-venous fistula (AV fistula) Internal arterio-venous graft (AV graft) Central venous catheter (also called central venous “line” or hemodialysis catheter) The AV graft An AV graft is a strong artificial tube inserted by a surgeon underneath the skin of your forearm, upper arm or thigh. One end of the tube connects to one of your arteries, and the other end connects to one of your veins (in the same limb). The graft may be straight or in the shape of a horseshoe.

6. Benefits of an AV graft „ A graft is usually the access method of choice if your veins are not suitable for a fistula. „ The graft can usually be used for hemodialysis two to four weeks after surgery. „ Once the incision is healed, there are no restrictions regarding showering or swimming. Surgery to create an AV graft A surgical procedure is needed to create the AV graft. An anesthetist will talk to you about the anesthetic that will be best for you during your surgery. After the surgery, it usually takes two to four weeks for the graft to be ready for use. Then, each time you have a hemodialysis treatment the dialysis nurse will insert two needles into your graft Care of your AV graft After the surgery, follow your surgeon’s instructions about your dressing and when the stitches (sutures) will be taken out. „ Check for a “thrill” which is the sensation like a vibration caused by blood flowing through your graft and can be felt just above your incision line. The “thrill” indicates the AV graft is working.

7. ARTERIOVENOUS (AV) FISTULA FOR HEMODIALYSIS Fistula—the gold standard access The National Kidney Foundation (NKF), Centers for Medicare and Medicaid Services (CMS) and Dialysis Patient Citizens (DPC) agree fistulas are the best type of vascular access. A fistula used for haemodialysis is a direct connection of an artery to a vein. Once the fistula is created it’s a natural part of the body. Once the fistula properly matures, it provides an access with good blood flow that can last for decades. It can take weeks to months before the fistula is ready to be used for haemodialysis. A fistula is the “gold standard” because: It has a lower risk of infection It has a lower tendency to clot It allows for greater blood flow and reduces treatment time It stays functional longer than other access types It’s usually less expensive to maintain While the AV fistula is the preferred access, some people are unable to have a fistula. If the vascular system is greatly compromised, a fistula may not be attempted. Some of the drawbacks of fistulas are: A bulge at the access site Lengthy maturation time or never maturing at all

8. Fistula care Cleanliness Cleanliness is one way someone on hemodialysis can keep their fistula uninfected. Keep an eye out for infections, which can often be detected when there is pain, tenderness, swelling or redness around the access area. If you notice fever, contact your doctor.. Unrestricted blood flow Any restriction of blood flow can cause clotting. Here are some tips to help avoid restriction: Avoid tight clothing or jewelry over your access area. Don’t carry heavy items over your access area. Have your blood pressure taken and blood drawn from your non-access arm. Don’t sleep with your access arm under your head or pillow. Check the pulse in your access daily.

9. CENTRAL VENOUS CATHETER To start hemodialysis treatment immediately, central venous catheter insertion is the most common and effective method. This method of vascular access is ideal for short-term use until a fistula or graft is ready. For hemodialysis, catheter is inserted into a large vein in either neck, chest, or leg near the groin (internal jugular, sub-clavian and femoral veins respectively). With this catheter more than 300 ml/min blood can be withdrawn for dialysis. Catheters are flexible, hollow tubes with two lumens. Blood is withdrawn from one lumen, enters the dialysis circuit, and is returned to the body via the other lumen. Venous catheters are commonly used for temporary access because of the risk of infection and clotting. Two types of venous catheters are available, tunnelled (usable for months) and non-tunnelled (usable for weeks).

10. http://www.kidneyfund.org/kidney-disease/esrd-treatment/vascular- access/?referrer=https://www.google.co.in/ https://www.nlm.nih.gov/medlineplus/ency/patientinstructions/000157.htm

11. DIALYZER

12. TYPES OF DIALYZERS A dialyzer is an artificial kidney designed to provide controllable transfer of solutes and water across a semi permeable membrane separating flowing blood and dialysate streams. The transfer processes are diffusion (dialysis) and convection (ultra-filtration). There are three basic dialyzer designs: coil, parallel plate, and hollow fiber configurations Coil dialyzer This artificial kidney was the first to be mass produced. It consisted of one or two long membrane tubes placed between support screens and then tightly wound around a plastic core. This design had serious performance limitations, which gradually restricted its use as better designs evolved. The coil design did not produce uniform dialysate flow distribution across the membrane. More efficient devices have replaced the coil design.

13. Parallel Plate Dialyzers(kill dialyzer) Sheets of membrane are mounted on plastic support screens, and then stacked in multiple layers ranging from 2 to 20 or more. This design allows multiple parallel blood and dialysate flow channels with a lower resistance to flow. The physical size of the parallel plate dialyzers has been greatly reduced since their introduction. There have been major improvements which provide (1)thinner blood and dialysate channels with uniform dimensions, (2)minimal masking or blocking of membranes on the support, and (3)minimal stretching or deformation of membranes across the supports.

14. Hollow Fiber for Dialyzer, Polysulfone Membrane Images Hollow Fiber for Dialyzer Internal detail

15. The wall of each hollow fiber is a semi-permeable membrane. The pores in this membrane are permeable for water and small molecules, while blood cells and larger molecules, such as proteins, are unable to pass the membrane. Uremic substances pass from the blood to the dialysis solution according to the principle of diffusion and through convections in ultrafiltration. During the dialysis treatment the dialyzer eliminates uremic substances and water are filtered out, and the purified blood is returned through the tubing into the body. Dialysis patients usually undergo three treatments per week with an average duration of 4-5 hours. Ultra filtration: All excess fluid must be removed from the bloodstream as the patient's blood flows through the dialyzer. The process of water removal from the bloodstream is called ultra filtration, and the amount of fluid removed is the ultra filtrate. Hollow Fiber Dialyzer: This is the most effective design for providing low-volume high efficiency devices with low resistance to flow. The fibers in the device are termed the fiber bundle. The fibers are potted in polyurethane at each end of the fiber bundle in the tube sheet, which serves as the membrane support.