Renal Replacement Therapies

Transcription

1 Renal Replacement Therapies M I H Á L Y T A P O L Y A I, M D, F A S N, F A C P A s s o c i a t e P r o f e s s o r D e p a r t m e n t o f N e p h r o l o g y L o u i s i a n a S t a t e U n i v e r s i t y S h r e v e p o r t, L A F r e s e n i u s M e d i c a l C a r e, S e m m e l w e i s U n i v e r s i t y B u d a p e s t 1 0 / 0 3 /

2 Renal Functions that Fail in Kidney Disease Diminished detoxification/ GFR decreased clearance: Uremia and death Drug accumulation: e.g.: vancomycin, digoxin, Acids (acidosis) Diminished metabolism of substrates: eg.: homocysteine: increased atherogenesis accumulation of waste products: inhibitors: e.g.: CHF (mediators of heart failure); anemia? Diminished fluid removal: expanded vascular space: HTN, CHF Diminished/ Abnormal Hormone Production (the kidney as an endocrine organ): Erythropoietin, Divalent Metal Binding Globulin: anemia vit. D3 activation: hyperparathyroidism

3 Definitions: CKD vs. ESRD vs. ARF Chronic Kidney Disease (CKD) refers to a disease state where the renal function is diminished but does not necessitate renal replacement therapy End-Stage Renal Disease (ESRD) refers to the absence of renal function to such a degree that survival would be jeopardized if renal replacement therapy was not provided Acute Renal Failure (ARF) is a condition when the renal function is lost suddenly, within minutes to days Acute renal injury: eg.: radio-contrast, nephrotoxic medications (aminoglycosides), atheroembolization, obstruction, etc. Rapidly progressive autimmune process: eg.: RPGN Renal replacement therapy may be necessary for survivors within days

4 Definitions: Renal Failure It is the CLEARANCE FUNCTION that we refer to when discussing loss of renal function. The loss of all functions can have catastrophic consequences but the most immediately noticed loss is that of clearance The loss of clearance is accompanied with the loss of other function losses

5 Incident & prevalent dialysis patient counts, & transplant patient counts The total number of renal failure patients is increasing but over the years this increase has been slowing down. USRDS data include patients identified by the CMS ESRD program & the UNOS transplant program.

6 Adjusted incident rates & annual percent change Incident ESRD patients. Rates adjusted for age, gender, & race.

7 Etiologies of ARF This is usually a hospitalacquired complication Complications of: Cardiac catheterization: atheroembolization Radio-contrast Excessive diuresis The most common cause of ARF is intravascular volume depletion (fluid loss) Even when volume depletion is not identified, it can be implicated Liano F; Pascual J Kidney Int 1996 Sep;50(3): patients in 13 Hospitals

8 Acute Renal Failure Loss of clearance Acute accumulation of waste products, toxins Loss of acid-base control Metabolic acidosis Loss of electrolyte control Hyperkalemia, hyperphosphatemia, hypermagnesemia Loss of drug removal or drug metabolism Drug toxicities: eg.: digoxin Loss of fluid clearance (+/-) Oliguric renal failure vs. non-ologuric real failure

9 Oliguria vs. Non-Oliguria Urine output renal function Complete loss of renal function may be present with normal U/O Normal GFR = 100 ml/min = 100 x 1440 min/day = ml/day = 144 L/day If 2 L/d U/O/day then 142 is must be reabsorbed Diuretics interfere with this re -absorption, they do not improve GFR! Oliguria is a marker of the severity of injury, may be a prognosticator

10 Glomerular Filtration If the filtration is ml/min then in minutes the entire blood volume would be drained in 1 day, 144 liters of ultrafiltrate is generated but only ~2 liters of urine

11 Treatment of Non-Clearance Function of Renal Failure The non-clearance function can be managed by medications: Anemia: Intravenous Iron Erythropoietin Metabolic Acidosis: Bicarbonate or citrate supplementation Fluid accumulation: Diuretics Diet: salt and fluid restriction

12 Renal Replacement Therapies RRT does not replace all aspects of renal function Patients on RRT still need medical treatments of all aspects of renal function RRT primarily focuses on supplying clearance RRT is not a cure, it is only a treatment of a chronic condition RRT s: Hemodialysis Peritoneal dialysis Transplantation

13 Transplantation RENAL REPLACEMENT THERAPIES

14 Adjusted rates of mortality, by age Prevalent adult Medicare patients. ESRD (dialysis & transplant): patients point prevalent on January 1, 2002 & with Medicare as a primary payor. CKD & non-ckd (general Medicare patients): included patients survive a one-year entry period in 2001, have continuous Medicare coverage with no HMO coverage, & do not have ESRD; CKD & diabetic status are defined during the one-year entry period. Followup is a maximum of two years, from January 1, 2002, to December 31, Events are defined by the first cause-specific inpatient ICD-9-CM diagnosis code during followup. Rates are adjusted for gender, race, & diabetic status. The reference cohort consists of all included patients (ESRD, CKD, & non-ckd). In any age group, renal patients have a higher mortality rate Even CKD patient have a much higher mortality rate, compared to the general population The reason for transplantation is not only an improvement in the quality of life but also in the quantity of life transplanted patients have as good of a chance to survive as those who have no kidney disease patients SURVIVAL!

15 Transplant patients have less myocardial infarction Figure 6.61 Adjusted rates of myocardial infarction, by age Prevalent adult Medicare patients. ESRD (dialysis & transplant): patients point prevalent on January 1, 2002 & with Medicare as a primary payor. CKD & non-ckd (general Medicare patients): included patients survive a one-year entry period in 2001, have continuous Medicare coverage with no HMO coverage, & do not have ESRD; CKD & diabetic status are defined during the one-year entry period. Followup is a maximum of two years, from January 1, 2002, to December 31, Events are defined by the first cause-specific inpatient ICD-9-CM diagnosis code during followup. Rates are adjusted for gender, race, & diabetic status. The reference cohort consists of all included patients (ESRD, CKD, & non-ckd).

16 Transplant patients have less stroke Figure 6.84 Prevalent stroke, by age, race & modality Per 100 patient years. Period prevalent ESRD patients, 2003.

17 Transplant patients have less infection! Figure 6.66 Adjusted rates of bacteremia/septic emia, by age Prevalent adult Medicare patients. ESRD (dialysis & transplant): patients point prevalent on January 1, 2002 & with Medicare as a primary payor. CKD & non-ckd (general Medicare patients): included patients survive a one-year entry period in 2001, have continuous Medicare coverage with no HMO coverage, & do not have ESRD; CKD & diabetic status are defined during the one-year entry period. Followup is a maximum of two years, from January 1, 2002, to December 31, Events are defined by the first cause-specific inpatient ICD-9-CM diagnosis code during followup. Rates are adjusted for gender, race, & diabetic status. The reference cohort consists of all included patients (ESRD, CKD, & non-ckd).

18 Transplant patients have less hip fracture Figure 6.67 Adjusted rates of hip fracture, by age Prevalent adult Medicare patients. ESRD (dialysis & transplant): patients point prevalent on January 1, 2002 & with Medicare as a primary payor. CKD & non-ckd (general Medicare patients): included patients survive a one-year entry period in 2001, have continuous Medicare coverage with no HMO coverage, & do not have ESRD; CKD & diabetic status are defined during the one-year entry period. Followup is a maximum of two years, from January 1, 2002, to December 31, Events are defined by the first cause-specific inpatient ICD-9-CM diagnosis code during followup. Rates are adjusted for gender, race, & diabetic status. The reference cohort consists of all included patients (ESRD, CKD, & non-ckd).

19 Transplant patients have less dementia Figure cohort: point prevalent patients alive during , with dialysis modality defined on December 31, Transplant patients received graft during , & had a functioning graft on 31 December The 2003 cohort is defined analogously. Occurrence of prevalent dementia, by age, dementia type, & modality

20 Why don t all of our ESRD patients have a transplant kidney? it is hard to get a kidney long waiting list few relatives or friends willing to donate Many patients do not qualify: Advanced age: risk of malignancy and complications Recent (<5 yrs) history of cancer: risk of recurence Other problems: Morbid obesity Poor cardiac/ pulmonary/ hepatic function psychiatric it is hard to keep a kidney! Acute rejection Chronic rejection Drug toxicities

21 Therapeutic Options in ESRD Living Related Renal Transplant (the best!) Living Un-Related Renal Transplantation Cadaveric Renal Transplant Hemodialysis Peritoneal dialysis (CCPD, CAPD &c.) Death

22 Transplant kidney placement The surgical site is the iliac fossa Iliac artery Iliac vein ureter

23 Transplant rates, 2003 USA Data presented only for those countries from which relevant information was available. All rates are unadjusted.

24 Complications of kidney transplantation Surgical complications: Bleeding, infection, technical failure Anesthesia-related complications Immunosuppression-related complications: Cancer; a much higher chance of cancers: De novo cancers: Skin, non-hodgkin s lymphoma, solid tumors Recurrence of old cancers Infections: Life threatening infections: Viral: CMV, herpes Bacterial infections Mortality after transplantation in the first 6-12 months is greater than any other RRT Loss of transplant: Acute: after the transplantation Chronic: slow degradation of renal function; average allograft survival ~12 years

25 hemodialysis RENAL REPLACEMENT THERAPIES

26 Hemodialysis The form of renal replacement therapy that can replace the clearance function and ultrafiltration function lost during renal failure (acute or chronic) Dialysis is achieved by diffusion of toxic waste products using a semipermeable membrane Blood is pumped through capillaries Water (dialysate) is pumped around the capillaries in a countercurrent manner Diffusion occurs because of a concentration gradient

27 Definitions: Dialysis Dialysis by diffusion through a semipermeable membrane No fluid removal Waste product, electrolytes moved across the membrane Q b Q d

28 Definitions: Ultrafiltration Ultrafiltration by convection using transmembrane pressure (hydrostatic and/or oncotic) Q b Only fluid is removed No clearance UF UF

29 Hemodialysis Hemodialysis is achieved through a connection between the artery and a vein: the AV Fistula Blood is pumped through the filter There is a need for anticoagulation

30 Hemodialysis Need for a vascular access: the greatest drawback Adequate clearance and ultrafiltration can be achieved Requires a center to go to but can be done at home as well Expensive Usually takes about 4 hours 3x per week

31 Indication for hemodialysis Progressive loss (in CKD) or acute loss (ARF) of the clearance of renal function to such a degree that survival is jeopardized if such function is not provided AND when medications and other therapies can no longer achieve this Uremia Metabolic acidosis Hyperkalemia or other electrolyte derangements Severe volume overload Poisoning

32 Dialysis access: Arterio-Venous Fistula

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34 Contraindications to hemodialysis There are not too many contraindications (there are no medical contraindications) Patient s choice Moribund patient

35 Complications of hemodialysis Need for access: Dialysis fistula Temporary dialysis catheter Catheter associated infection Catheter associated stenosis after the catheter is removed Clotting of the dialysis circuit: Need for anticoagulation Heparin-related complications: Accidental events: Excessive bleeding Heparin-induced Thrombocytopenia Blood leaks; disconnects Wrong dialysate solution Expense: the most expensive form of RRTx Other dialysis-associated complications are renal-failure associated rather than dialysis-related: eg. Anemia, hyperparathyroidism, bone disease, fluid overload etc.

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37 Peritoneal dialysis RENAL REPLACEMENT THERAPIES

38 Peritoneal dialysis Peritoneal dialysis is a form of self-administered renal replacement therapy It relies on the patient The patient is only seen once a month to check on her progress and check her labs If problems arise, they can call by the phone

39 Peritoneum The peritoneum can act as a membrane both for: Ultrafiltration And clearance Living membrane Ultrafiltration is achieved through the osmotic pressure of glucose The dialysis fluid is a glucose solution Clearance is achieved because of diffusion through the membrane over time The surface area is about 2 m 2, about the same as the surface area of a dialysis filter

40 The peritoneal cavity

41 Clearance through the peritoneal membrane Large pores A < 0.1% of all pores. transport macromolecules Small pores A more numerous transport small solutes and water. Transcellular pores (4-6 A) aquaporin-1 Rippe B. A. Perit Dial Int 13 Suppl 2:S35-S38, 1993 Rippe B, Krediet RT. Gokal R, Nolph KD, eds. The textbook of peritoneal dialysis. Kluwer 1994:69-113

42 Peritoneal dialysis Peritoneal dialysis catheter placement is usually not a problem Adequate clearance and ultrafiltration can be achieved: glucose solution Requires a center to go to once a month but can be done at home The least expensive modality of RRTx Usually takes about 8 hours a day but fluid is left in the peritoneal cavity 24 hours a day If manually exchanged, then 4-5 exchanges are needed a day, this is call Continuous Ambulatory Peritoneal Dialysis (CAPD) If a machine does the exchanges at night then Continuous Cycled Peritoneal Dialysis (CCPD) The modality survival is about 2 years The quality of the peritoneal membrane changes and loses its ability to ultrafiltrate

43 Connecting the PD catheter to the bags

44 Patient Selection for PD Contraindications: patient unwilling patient unable morbid obesity history of abdominal surgeries lack of manual dexterity The choice is exclusively by Patient preference and Physician s comfort

45 CCPD

46 Complications of peritoneal dialysis Infections: Exit site infection Catheter-related infection Peritonitis Progressive Encapsulating Sclerosing Peritonitis Very rare complication Fibrous transformation of the visceral connective tissues leading to death Catheter placement related complications: Hemorrhage Visceral puncture (technical problems)

47 Adjusted 5-year survival, by modality & primary diagnosis The yearly mortality rate of dialysis patient is about 20-25% Incident dialysis patients; adjusted for age, gender, & race. ESRD patients, 1996, used as reference cohort. Modality determined on first ESRD service date; excludes patients transplanted or dying during the first 90 days (five-year survival probabilities noted in parentheses).

48 Hemodialysis vs. Peritoneal Dialysis Hemodialysis Chronic renal failure Acute renal failure (drug toxicity or poisonous substances) Presence of abdominal surgery or scar (PD cannot be performed) Peritoneal Dialysis Infants and children Acute renal failure Temporary measure while vascular access is healing in case of hemodialysis Convenience or patient preference Economy (PD is less expensive) Outcome and survival are the same

49 Quality of Life on Dialysis Chronic low back pain patients report (Atributional Style Questionnaire) similar index of depression as chronic hemodialysis patients (misery index) Cheatle MD et al. Clin J Pain 1990 Jun;6(2):

50 Summary Renal failure, acute or chronic, is a complex disease leading to a high degree of mortality and complications that can be altered with good care. Renal replacement therapies are therapies only, not a cure The best therapy is a kidney transplant, however, many patients do not qualify and if they qualify they do not get a kidney; then their form of therapy is usually their choice

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