Renal dialysis


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Renal dialysis

  2. 2. • The three primary treatment options for patients with end-stage renal disease (ESRD) are • hemodialysis (HD) • peritoneal dialysis (PD) and • kidney transplantation • when person lose about 85 to 90 percentwhen person lose about 85 to 90 percent of kidney function.of kidney function.
  3. 3. RENAL DIALYSIS • Definition: The process of filtering the blood, the way kidneys normally do, using a machine. • Renal Dialysis is a process of artificial duplication of the kidney function for separating crystalloid and colloid substances from the blood using a semi- permeable membrane (cellulose- acetate membrane tube immersed in fluid) . • The processes of diffusion and convection [movement from high to lower pressure region] are used for solute removal, and a combination of osmosis and ultra filtration are used to normalise body water.
  4. 4. • The kidneys purify the blood by filtering it and then selectively reabsorbing water and useful molecules. Each kidney is made up of about one million microscopic filter units called nephron and acts independently of the other. • Waste products from the filtering process are flushed through the ureters to the bladder and excreted as urine. For person whose kidneys are diseased or no longer perform their normal function without assistance, the Renal Dialysis process performs two functions, it: • removes metabolic waste products • temporarily restores imbalances in body water and electrolyte concentration
  5. 5. • The dialysis therapies that are available are • Peritoneal dialysis, where the semi permeable nature of the peritoneal [abdominal] membrane is used to achieve the normalisation of body fluids, and • Haemodialysis, where an artificial kidney or dialyser is used.
  6. 6. • The most common causes of renal disease are: • Glomerulonephritis inflammation of the kidney [caused by a variety of conditions]. • Diabetes: an inability to correctly utilise the hormone insulin. • Hypertension: high blood pressure. • Analgesic Nephropathy disease caused by the prolonged use of specific analgesics [pain killers]
  7. 7. Haemodialysis: a Replacement for Renal Function • It is commonly prescribed for 3 times per week and each session lasts from 4-5 hours. • Each client receives between 12 and 15 hours of Haemodialysis each week. • The dialyser is usually cylindrical in shape and approximately 25-30 cm [10-12 inches] long . It is made up of two compartments separated by a fabric [membrane] semi-permeable in nature. • The compartment containing the client's blood is called the blood compartment. The dialysate compartment contains the dialysate solution which is comparable to the body fluids of a person with normally functioning kidneys.
  8. 8. • A patient has two catheters, or small tubes, inserted. One catheter is placed in a vein and the other in an artery. • The arterial catheter removes the blood from the patient where it then travels into a dialysis machine. • The dialysis machine filters the blood to rid it of waste products, similar to the way the kidneys normally do. The filtered blood then returns to the patient through the venous catheter.
  9. 9. dialysis machine • The machine performs two primary functions: • production and monitoring of dialysate • pumping and monitoring of blood through the extra-corporeal circuit. • Modern dialysis equipment monitors fluid flow in and out of the dialyser and very accurately controls the weight loss
  10. 10. Dialysate • Dialysate passes through the dialysate compartment at the rate of 500ml/minute. As a result, 30 litres /hour are required for each 4-5 hour session. • The used dialysate is not recyclable with most machines. Commonly, 600 litres per week of dialysate is required. • To maintain these volumes economically for the client , a mixture of concentrated electrolyte solution is diluted with purified water using the machine at the site of the dialysis.
  11. 11. Dialysis membrane • dialyzers are hollow fiber devices that contain thousands of hollow fibers housed in a hard plastic, typically polycarbonate, shell. Blood flows through the dialyzer on the interior (lumen) of the fibers. Dialysate flows through the dialyzer on the exterior (shell-side) of the fibers. • Cellulose acetate or polysulfone • The dialysis membrane is permeable to all solute that is less than 2000 daltons in size and, to a lesser degree, to solutes up to 5000 daltons. As a result, electrolytes and metabolic waste products such as urea and creatinine can easily pass through, while larger elements, such as blood cells and proteins are retained.
  12. 12. Composition of dialysate • Glucose serves as the osmotic agent that enhances ultrafiltration1.5% to 4.25% dextrose • The sodium concentration in the ultra filtrate during peritoneal dialysis is usually less than that of extra cellular fluid, so there is a tendency toward water loss and development of hypernatremia so dialysates have a sodium concentration of 132 mEq/L to compensate for this tendency toward dehydration. • Bicarbonates(22mmol/L) to rectify metabolic acidosis. • Magnesium concentrations of 0.375 and 0.5 mmol/L (i.e., 0.75 and 1.0 mEq/L or 0.9 and 1.2 mg/dL) are most frequently used. • Phosphorus concentrations have varied from 0.65 to 2.6 mmol/L,
  13. 13. Continued…. • Calcium concentrations below 1.5 mmol/L, • 1,25-dihydroxyvitamin D can be liberalized to reduce circulating levels of parathyroid hormone and, thus, the risk of inducing hypercalcemia. • tCO2 concentration above 23 mmol/L Increasing evidence suggests that correction of chronic acidosisis of clinical benefit in terms of bone metabolism and nutrition. • The use of an ethanol-enriched dialysate, along with intravenous ethanol administration, has been found to be helpful in the management of patients with methanol poisoning.3 A dialysate ethanol level of 100 mg/dL (22 mmol/L) is often used
  14. 14. • intravenous administration comprise iron dextran, iron saccharate (from 2 to 70 mg/dL) (iron sucrose), and iron gluconate. The administration of all these iron formulations can be associated with hypotension and anaphylactoid reactions. • urea concentration is high prior to dialysis, there is a risk of developing the dialysis disequilibrium syndrome. • Transport rate of low MW solutes >> high MW solutes.
  15. 15. MOLECULAR WEIGHT • Urea 60 • Creatinine 113 • glucose 180 • Beta 2-microglobulin 11,600 • albumin 68,000
  16. 16. Principle involve in dialysis • 1. Diffusion is the exchange of things dissolved in fluid (solutes) across the membrane due to differences in the amounts of the solutes on the two sides (concentration gradient). • If there is a higher concentration of a given solute on one side of the membrane than on the other, then diffusion will occur . By controlling the chemicals in the dialysate, the dialysis machine controls this transfer of solutes according to the doctor's prescription. • Dialysis machines control the chemicals in the dialysate by mixing dialysis fluid concentrates, which are strong versions of the chemicals, (acetate or sodium bicarbonate plus acetic acid based solutions) with purified water.
  17. 17. • 2. Ultrafiltration, also referred to as convection, is fluid flow through the membrane, forced by a difference in pressure on the two sides of the dialyzer (pressure gradient). • This controls the patient's weight loss over the course of the treatment. While earlier dialysis machines either controlled dialysate pressure or the pressure difference across the membrane in order to achieve ultrafiltration, modern dialysis machines are generally volumetric, meaning they control the volume of fluid removed from the patient directly and allowing dialysate pressure to change as it will in order to achieve the prescribed weight loss. • Volumetric control is generally achieved either by controlling the flow of dialysate in and out of the dialyzer 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.
  18. 18. • Osmosis is the net movement of water across a selectively permeable membrane driven by a difference in the amounts of solute on the two sides of the membrane. • In dialysis, this refers not to water movement across the hemodialyzer membrane, but across cell membranes within the body-either from within the red cells to the blood plasma, or from within cells of the various tissues in the body (like muscles) 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 sodium level of the plasma
  19. 19. Peritoneal Dialysis (PD) • Dialysis fluid is introduced to the peritoneal cavity through a catheter placed in the lower part of the abdomen. • A thin membrane, called the peritoneum, lines the walls of the peritoneal cavity and covers all the organs contained in it. • In PD the peritoneum serves as the dialysis membrane. The peritoneal cavity can often hold more then 3 litres, but in clinical practice only 1.5 – 2.5L of fluid are used. • This is an intra-corporeal blood purification as no blood ever leaves the body of the patient.
  20. 20. The abdominal cavity, hold the large organs of the digestive system, is lined by the peritoneum. In PD, special fluid is instilled through a permanent catheter in the lower abdomen.
  21. 21. • An osmotic pressure gradient is applied by the addition to the dialysis fluid of an osmotic agent which will “suck” fluid from the blood. • The concentration of this osmotic agent is chosen to give just the fluid removal needed. In most cases glucose is used to create the osmotic pressure. • Fluid is removed by ultra-filtration driven by an osmotic pressure gradient. (Eg. Yellow/Green/Red Bags)
  22. 22. • The abdominal cavity and all the organs contained in it are lined by a thin smooth membrane, the peritoneum. • It is a loose connective tissue containing blood vessels and nerves. • If put under the microscope, three layers can be identified between the peritoneal cavity and the blood stream. • The capillary wall / the interstitium / the mesothelium • Each of these is a barrier to the transport of fluid and solutes.
  23. 23. • Solutes are transported across the membrane by diffusion.The driving force is the conc gradient between the PD fluid and the blood.Waste products present in the blood per fusing the peritoneum will diffuse from the blood vessels into the “cleaner” dialysis fluid.
  24. 24. • The dialysis fluid should be instilled for 4 to 6 hours. • When the dialysis fluid is drained from the abdominal cavity, it contains waste products and excess fluid extracted from the blood. • PD is most often applied and effective as a continuous therapy. In this way it is a more physiological treatment then Haemodialysis (HD)
  25. 25. RENAL TRANSPLANTATIONRENAL TRANSPLANTATION • A kidney transplant is an operation in which a person whose own kidneys have failed receives a new kidney to take over the work of cleaning their blood. • All patients with ESRD are candidates for KT unless - • Systemic malignancy. • Chronic infection. • Severe cardiovascular disease. • Neuropsychiatric disorder. • Extremes of age (relative).
  26. 26. KIDNEY DONORKIDNEY DONOR • Living related.Living related. • Living unrelated (emotionally motivated).Living unrelated (emotionally motivated). • Cadaveric (Brain-dead)Cadaveric (Brain-dead) • Beating and non-beating heartBeating and non-beating heart
  27. 27. CRITERIA FOR LIVING DONORCRITERIA FOR LIVING DONOR SELECTIONSELECTION - Blood relative.Blood relative. - Highly motivated.Highly motivated. - ABO blood group-compatible.ABO blood group-compatible. - HLA-identical or haploidentical withHLA-identical or haploidentical with negative cross-match.negative cross-match. - Excellent medical condition with normalExcellent medical condition with normal renal function.renal function.
  28. 28. CRITERIA FOR CADAVERCRITERIA FOR CADAVER DONOR SELECTIONDONOR SELECTION - Irreversible brain damage.Irreversible brain damage. - Normal renal function appropriate for age.Normal renal function appropriate for age. - No evidence of preexisting renal disease.No evidence of preexisting renal disease. - No evidence of transmissible diseases.No evidence of transmissible diseases. - ABO blood group-compatible.ABO blood group-compatible. - Negative cross-match.Negative cross-match. - Best HLA match possible, particularly at the DRBest HLA match possible, particularly at the DR and B loci.and B loci.
  29. 29. Principles Involved In evaluating APrinciples Involved In evaluating A Prospective Living Kidney DonorProspective Living Kidney Donor  Whether there is a medical condition that willWhether there is a medical condition that will put donor at increased risk for complicationsput donor at increased risk for complications for general anaesthesia or surgery.for general anaesthesia or surgery.  Whether the removal of one kidney willWhether the removal of one kidney will increase the donor’s risk for developing renalincrease the donor’s risk for developing renal insufficiency.insufficiency.
  30. 30. Evaluation Of Kidney Function InEvaluation Of Kidney Function In Potential Kidney DonorPotential Kidney Donor  Serum creatinine.Serum creatinine.  Creatinine clearance.Creatinine clearance.  Radionuclide glomerular filtration rate.Radionuclide glomerular filtration rate.  Urine analysis.Urine analysis.  Urine Culture.Urine Culture.  GFR > 70 ml/minGFR > 70 ml/min..
  31. 31. Medical Conditions That Exclude LivingMedical Conditions That Exclude Living Kidney DonationKidney Donation  Renal parenchymal disease.Renal parenchymal disease.  Conditions that may predispose to renal diseaseConditions that may predispose to renal disease History of stone diseaseHistory of stone disease History of frequent UTIHistory of frequent UTI HypertensionHypertension D.M.D.M.  Conditions that increase the risks of anaesthesia andConditions that increase the risks of anaesthesia and  Recent malignancyRecent malignancy..
  32. 32. CONTRAINDICATIONS TO RENALCONTRAINDICATIONS TO RENAL TRANSPLANTATIONTRANSPLANTATION - ABO incompatibility.ABO incompatibility. - Cytotoxic antibodies against HLA antigens of donor.Cytotoxic antibodies against HLA antigens of donor. - Recent or metastatic malignancy.Recent or metastatic malignancy. - Active infection.Active infection. - AIDS.AIDS. - Severe extra renal disease (cardiac, pulmonary, hepatic).Severe extra renal disease (cardiac, pulmonary, hepatic). - Active vasculitis or glomeurlonephritis.Active vasculitis or glomeurlonephritis. - Uncorrectable lower urinary tract disease.Uncorrectable lower urinary tract disease. - Noncompliance.Noncompliance. - Psychiatric illness including alcoholism and drug addiction.Psychiatric illness including alcoholism and drug addiction. - Morbid obesity.Morbid obesity. - Age > 70 years.Age > 70 years. - Primary oxalosis .Primary oxalosis . - Persistent coagulation disorder.Persistent coagulation disorder.
  33. 33. Matching between Recipient And DonorMatching between Recipient And Donor A- Tissue typingA- Tissue typing • Determined by 6 antigens located on cell surfaceDetermined by 6 antigens located on cell surface encoded for by the HLA gen located on the short arm ofencoded for by the HLA gen located on the short arm of chromosome 6.chromosome 6. • Class I antigens (HLA-A and HLA-B) are expressed onClass I antigens (HLA-A and HLA-B) are expressed on the surface of most nucleated cells.the surface of most nucleated cells. • Class II antigen (HLA-DR) are expressed on surface ofClass II antigen (HLA-DR) are expressed on surface of APC and activated lymphocytes.APC and activated lymphocytes. • These 6 antigens are referred to as major transplantThese 6 antigens are referred to as major transplant antigens.antigens. • The match between donor and recipient can range fromThe match between donor and recipient can range from 0 to six.0 to six.
  34. 34. Matching between Recepient And DonorMatching between Recepient And Donor B- Cross matchingB- Cross matching • A laboratory test that determines weather a potentialA laboratory test that determines weather a potential transplant recepient has preformed antibodies against the HLAtransplant recepient has preformed antibodies against the HLA antigens of the potential donor. (Donor Lymphocytestantigens of the potential donor. (Donor Lymphocytest +Recepient Serum)+Recepient Serum) • A Final CM is mandatoryA Final CM is mandatory C- Compatible ABO blood group.C- Compatible ABO blood group.
  35. 35. What Are The Major Causes Of Long-What Are The Major Causes Of Long- Term Allograft Failure ?Term Allograft Failure ? • Chronic rejection.Chronic rejection. • Death with functioning graft.Death with functioning graft.
  36. 36. CLINICAL ALLERTS ASSOCIATED WITH RENAL IMPAIREMENT • Drug needing monitoring • ACE inhibitors: captopril , enalapril • Analgesics :asprin , mepridine,NSAIDS • Antiarrhythmic agents: procainamide • Antibiotics : aminoglcosides ,cephalosporin , flouroquinolones ,sulphonamide etc • Antiepileptics: gabapentin ,topiramate • Antifungal • Antigout :allopurinols , colchicine • Antihistaminics • Antineoplastics :bleomycin etoposide ,mtx, • Antiviral: acyclovir , amantadine • Beta blockers :acebutolol ,atenolol , sotalol • Diuretics: acetrazolamide ,amiloride ,mannitolol, • Hypoglycemic agents :insulin , metformine • Muscle relaxants