Chronic kidney disease: definitions and optimal management

Chronic kidney disease: definitions and optimal management

Dr H BiermanDepartment of Nephrology

Objectives:• Definition of CKD• Prevalence and scope of CKD• Optimal management:• Delaying progression• Treatment of co morbidities• Transition to ESRDKidney disease outcomes initiative K/DOQI

www.kidney.org

Definitions and stages of CKD• Chronic > 3 months• Kidney damage:1. Hematuria/albuminuria2. Biopsy3. Abnormal imaging tests• Glomerular filtration rate < 60

NO MORE 24 HR URINES

– SPOT URINE IS ADEQUITE

FOR SCREENING

Quantification of proteinuria (positive dipstick):

NORMAL ABNORMAL

24 HR URINE PROTEIN <300 MG/24HR > 300 MG/25HR

URINE SPOT PROTEIN/CREATININE RATIO

<200 MG/G >200 MG/G

Quantification of proteinuria (negative dipstick):

NORMAL MICRO-ALBUMINURIA

Urine spot sample (ug/min)

< 20 20 – 200

Urine spot sample (mg/24hr)

< 30 30 – 300

Spot Albumin/creat ratio (mg/gm)

< 30 30 - 300

Evaluation of proteinuria in patients not known to have kidney disease.(10, 11)7.

Levey A S et al. Ann Intern Med 2003;139:137-147

©2003 by American College of Physicians

Serum creatinine is an inadequate screening test for renal failure, especially in the

elderlySensitivity = 12.6 %Specificity = 99.9%

(Swedco PJ... Arch Int Med.2003;163:356-360)

Methods of estimating GFR• Inulin clearance “gold standard”• Creatinine clearance = 24 hr unine

collection• Equasions based on serum creatinine 1. Cockroft-Gault *2. MDRD (modification of diet in renal disease)

MDRD equation for predicting GFR Modification of diet in renal disease study JASN2000

• GFR (ml/min/1.73m2)= 186 x Pcr -1.154 x age -0.203 x1.212 if

black X0.742 if femaleThe MDRD equation calculates GFR, hence

values are lower than those of creatinine clearance by Cockcroft Gault equation.

Cockcroft-Gault equation:

• Cr Cl =(140-age) x wt/72(serum Cr)

Decrease 15% for womenDecrease 20% for paraplegia,40% for

quadriplegiaIncrease 12% for AA males

K/DOQI CKD Staging

Require 2 or more GFR’s 3 or more moths apart

GFR 90 60 30 15

Other markers of kidney disease: proteinuria, hematuria,

anatomic

Complications possible

Complications evident

Renal replacement

1 2 3 4 5

Stages of chronic kidney disease

National Kidney Foundation Kidney Disease Outcomes Quality Initiative Classification, Prevalence, and Action Plan for Stages of Chronic Kidney Disease.

Levey A S et al. Ann Intern Med 2003;139:137-147

©2003 by American College of Physicians

Clues to the Diagnosis of Chronic Kidney Disease from the Patient's History.

Levey A S et al. Ann Intern Med 2003;139:137-147

©2003 by American College of Physicians

Prevalence of Persons at Increased Risk for Chronic Kidney Disease.

Levey A S et al. Ann Intern Med 2003;139:137-147

©2003 by American College of Physicians

Laboratory Evaluation of Patients with Chronic Kidney Disease and Persons at Increased Risk for Chronic Kidney Disease.

Levey A S et al. Ann Intern Med 2003;139:137-147

©2003 by American College of Physicians

Etiology of end stage renal disease

• Diabetes 74%• Hypertension 39.3%• Glomerulonephritis 16.5%• Secondary GN/vasculitis 3.8%• Interstitial nephritis/pyelonephritis 6.5%• Cystic/hereditary/congenital 5.5%• Neoplasms and tumours 3.3%• Other 12.6%

Treatment to Prevent Progression of CKD to Kidney Failure

• Intensive glycemic control lessens progression from microalbuminuria in type 1 diabetes

- DCCT, 1993• Antihypertensive therapy with ACE Inhibitors/ARB’s

lessens proteinuria and progression - Giatras, et al., 1997

- Psait, et al., 2000 - Jafar, et al., 2001 • Low protein diets lessen progression

- Fouque, et al., 1992 - Pedrini, et al., 1996 - Kasiske, et al., 1998

Who to Test for Chronic Kidney Disease

Regular testing of people at risk

• Diabetes

• Hypertension

• Relative with kidney failure

• Cardiovascular disease

How to Test for Chronic Kidney Disease*

In individuals with diabetes:• “Spot” urine albumin to creatinine ratio

In others at risk:• “Spot” urine albumin to creatinine ratio OR standard

dipstick (Bouleware, et al., 2003)• Estimate GFR from serum creatinine using the MDRD

prediction equation

*24 hour urine collections are NOT needed. Diabetics should betested once a year. Others at risk testing less frequently as long asnormal.

Who Should be Treated forChronic Kidney Disease

With diabetes:• With urine albumin/creatinine ratios more than

30mg albumin/1 gram creatinineWithout diabetes:• With urine albumin/creatinine ratios more than

300mg albumin/1 gram creatinine corresponding to about 1+ on standard dipstick

OrAny patient:• With estimated GFR less than 60 mL/min/1.73 m2

How to Treat for Chronic Kidney Disease

• Maintain blood pressure less than 130/80 mmHg

• Use an ACE Inhibitor or ARB• More than one drug is usually required and a

diuretic should be part of the regimen• Continue best possible glycemic control in

individuals with diabetes• Moderate Protein restriction

Blood pressure targets

CLINICAL STATUS BP GOALHypertension (no DM or renal disease)

< 140/90 mmHg (JNC7)

Diabetes mellitus < 130/80 mmHg (ANA, JNC7)

Renal disease (proteinuria > 1gm/24hrs, diabetic kidney disease)

< 130/80 mmHg< 125/75 mmHg (NKF)

Risk factors for cardiovascular disease

Traditional risk factors:• Age• Male Gender• Menopause• Family history• Hypertension• Smoking• High LDL, low HDL• Diabetes• Inactivity, obesity• LVH

NON-TRADITIONAL RISK FACTORS

• CaPO4 product• Anaemia• Inflammation• Hypoalbuminemia

“REVERSE EPIDEMIAOLOGY”

• Low cholesterol• Low body-weight• Low blood pressure

Management of co-morbidities in CKD

• Anaemia• Renal osteodystrophy• Hyperlipidemia

Benefits of correction of HbRaising the Hkt to 30-36%improves:• Brain and cognitive function• Quality of life• Exercise capacity/muscle function• ?LVH• ?Survival

Treatment of calcium, phosphate and osteodystrophy:

AIM is to normalise:• Serum calcium• Serum phosphate• PTHMethods:• Oral calcium• Vitamin D analogues• Phosphate binders• Calcimimetics

Preparation for renal transplant:• Choice of renal replacement• Timely access surgery• Timely dialysis initiation

Preparation for renal replacement:

When GFR < 25ml/min:• Renal transplant is the treatment of first

choice – work up living donors• If no donor available – 1. List patient on cadaver kidney waiting list2. Place angio-access – if HD planned

Peritoneal dialysis• method of RRT for 100.000 patients worldwide• complementary to hemodialysisPrinciples: • peritoneum (capillary endothelium, matrix,

mesothelium) = semipermeable dialysis membrane through which fluid and solute move from blood to dialysis solution via diffusion and convection

• effective peritoneal surface area = perfused capillaries close to peritoneum (↓ in peritonitis)

• ultrafiltration (movement of water) enabled by osmotic gradient generated by glucose or glucose polymers (isodextrin)

Scheme of peritoneal solute transport by diffusion through the pores of capillary wall

Peritoneal catheter

• implanted via laparoscopy, punction or laparotomy (total anesthesy)

• PD is started 3 weeks following the impantation of catheter

Why to start with PD ?

1. better maintenance of residual renal function

Why to start with PD ?

• clinical outcomes comparable to HD, no difference in 2 year and 5 year mortality vs. HD (study NECOSAD)

• saves vascular access • preferred for children (APD)• modality choice is a lifestyle issue

Indication / Contraindications of PD

80% of patients have no contra-indication to any of the dialysis methods and may choose according to their life style between HD a PD

Absolute contra-indications of PD: 1.peritoneal fibrosis and adhesions following

intraabdominal operations 2.inflammatory gut diseases

Haemodialysis:• Process by which the solute composition

of a solution “A” is altered by exposing it to a second solution “B” through a semi-permeable membrane

Indications for initiating Hemodialysis

• In patients with calculated creatinine clearance <20 ml/min/1.73 m2 the onset of:

*Uremic symptoms Nausea/emesis Altered sleep pattern *Altered mental status Coma Stupor Tremor Asterixis Clonus Seizures

Indications for Hemodialysis• Pericarditis or Tamponade (urgent

indication)• Uremic platelet dysfunction (urgent

indication)• Refractory volume overload• Refractory hyperkalemia• Refractory Metabolic acidosis with anuria

Indications for Hemodialysis• Steadily worsening renal function in a

patient with measured 24 hour urinary creatinine clearance<15 ml/min when accompanied by worsening azotemia, poor nutritional status and refractory edema

Summery: definition of CKD• “spot” urine albumin/microalbumin to

creatinine ratio• Estimated GFR according to MDRD

prediction equation

Note: 24 hour urine collections not neededDM and Hpt – tested once per yearOthers at risk: less often as long as normal

Summery: optimal management of CKD

• Delay progressionACE-inh/ARBBP control – 130/85Blood sugar controlProtein restriction• Treat co-morbiditiesAnemiaRenal osteodystrophyHyperlipidemiaCardiovascular diseaseNutrition and acidosis

Preparation for renal replacementChoice of renal replacementTimely access surgeryTimely dialysis initiation

Thank you